State Descriptions

The state descriptions list the activities within each state. They should be considered as summaries of the measurement execution within each state and as a quick reference guide to understand the sequence of individual state events.

The description of each state is given in the form of a table. The table content is as follows

Header........................................

ILOS...........................................
Scan............................................

Swath..........................................

Measurement Duration.................

Exposure Control.........................
Integration Time...........................
Pixel Size (Ground Pixel)..............

state ID with acronym, the measurement type and measurement category
strategy and targeting of the instantaneous line of sight (ILOS)
type of scan, centre of scan motion, width, number of repetitions and velocity resp. duration
image of the scan of the instantaneous field of view (IFOV) on the earth surface
measurement duration, partly split into different measurement
phases
pixel exposure time
range of integration times = pixel exposure time × co-adding
spatial resolution (dependant on selected integration time)


The state descriptions presented here are those for nominal operations, i.e. they represent the final flight states as of January 2011 (FFS_021215 plus all OCRs requiring permanent modifications of this configuration). The final flight state version FFS_021215 had been uploaded December 15th, 2002. The OCRs are summarized in the OCR implementation table.

State ID State Acronym State ID State Acronym State ID State Acronym State ID State Acronym
01 nad01 19 ascd03 37 limb10 55 lmt01
02 nad02 20 ascd04 38 lnad01 56 mop01
03 nad03 21 ascd05 39 dcchm 57 mop02
04 nad04 22 asad01 40 limb13 58 sscp01
05 nad05 23 nad23 41 limb12 59 lsc01
06 nad06 24 nad24 42 nad26 60 sscs01
07 nad07 25 nad25 43 nad27 61 lwc01
08 dcc05 26 dcc04 44 nad28 62 escd02
09 nad09 27 elimb01 45 nad29 63 dcc02
10 nad10 28 limb01 46 dcc01 64 nmep01
11 nad11 29 limb02 47 sos02 65 adc01
12 nad12 30 limb03 48 lwnd01 66 nmes02
13 nad13 31 limb04 49 sos01 67 dcc03
14 nad14 32 limb05 50 scs01 68 nmes01
15 nad15 33 limb06 51 sop01 69 lsd01
16 lwnd02 34 limb11 52 escd01 70 lwd01
17 ascd01 35 limb08 53 sscp02    
18 ascd02 36 limb09 54 mos01    



State Description Tables

State ID 01
nad01
Scientific measurement Nadir
ILOS Description
In State 01 the Earth atmosphere is observed centering the line of sight (LOS) towards Nadir. To adjust the ILOS (Instantaneous Line of Sight), SCIAMACHY uses for the measurement only the nadir/elevation scan mirror (ESM).
Scan

By the orbital motion the atmospheric volume above the subsatellite point along the ground track is observed during the duration of the measurement. The scan motion of the ESM moves the ILOS in crosstrack direction. The basic position of the ESM is controlled by basic profile 1 yielding a position of -45.5°, corresponding to a slightly shifted nadir-direction (-z) for the ILOS. This shift is to avoid partial obscuration of the nadir pixels on the extreme right side of the scan.The motion of the ESM is controlled by relative scan profile 2, which yields an ILOS scan of about 61.6°. This profile produces a relative motion of the ESM (relative to -45.5° basic position) of fixed duration for 4 seconds in positive direction and a flyback (reverse motion) to the original angular position within 1 second. The 4 second forward motion produces a scan of the ground pixel in east-west direction (for the descending north-south pass of the orbit).
The resulting swath is reduced by 2° ILOS on its right side and maintains the original angular position on the left side.

Swath To adjust the Earth coverage the swath is set to 930 km by setting the scan speed to 16°/s. Centering of the scan gives a start position (for the descending north-south pass of the orbit) of the forward scan of 480 km left of the subsatellite point (ESM angular position at approx. -61°) and a turnaround position of the backward scan of 450 km right of the subsatellite point (ESM angular position -30°).
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
The exposure of the focal plane linear detector arrays (channels) is controlled by a subset of parameters setting the exposure times of the channels (6 plus 4 virtual) respectively the defined clusters and the corresponding co-adding factors. The exposure parameters for nad01 are set to produce optimal signals for the orbital position < -3° and > 183°. The definitions are summarised in PET table N1.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad01 low rate data they are listed in integration_time table 21.
Pixel size
(Ground pixel)
The ground pixel size is determined by the motion of the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 25 km × 0.6 km on ground - over the atmosphere during the integration time. The motion is a combined motion of the scan mirror and the orbital motion of the spacecraft. Since the integration time is diverse, and the angular speed for forward and flyback is different by a factor 4 the ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 26 km × 30 km.



State ID 02
nad02
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad02 are set to produce optimal signals for the orbital position -3° to 0° and 180° to 183°. The definitions are summarised in table PET table N2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad02 low rate data they are listed in integration_time table 22.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 26 km × 30 km.



State ID 03
nad03
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad03 are set to produce optimal signals for the orbital position 0° to 16° and 164° to 180°. The definitions are summarised in PET table N3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad03 low rate data they are listed in integration_time table 23.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32km × 233 km (along track × across track) and approx. 26 km × 30 km.



State ID 04
nad04
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad04 are set to produce optimal signals for the orbital position 16° to 26° and 154° to 164°. The definitions are summarised in PET table N4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad04 low rate data they are listed in integration_time table 24.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 26 km × 30 km.



State ID 05
nad05
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad05 are set to produce optimal signals for the orbital position 26° to 36° and 144° to 154°. The definitions are summarised in PET table N5.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad05 low rate data they are listed in integration_time table 25.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 26 km × 30 km.



State ID 06
nad06
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad06 are set to produce optimal signals for the orbital position 36° to 70° and 110° to 144°. The definitions are summarised in PET table N6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad06 low rate data they are listed in integration_time table 26.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 27 km × 59 km.



State ID 07
nad07
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01; speed 16°/s
Swath see state ID 01; width 930 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad07 are set to produce optimal signals for the orbital position 70° to 110°. The definitions are summarised in PET table N7.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad07 low rate data they are listed in integration_time table 27.
Pixel size
(Ground pixel)
see state ID 01
The ground pixel size varies between approx. 32 km × 233 km (along track × across track) and approx. 27 km × 59 km.



State ID 08
dcc05
Calibration Dark_Current_Calibration
ILOS Description
In State 08 the ILOS is pointing in flight direction to an altitude safely above the earth atmosphere (250 km above horizon, basic profile 9) to eliminate atmospheric influences on the dark current measurement. To adjust the ILOS, SCIAMACHY uses for the measurement the nadir/elevation scan mirror (ESM) and the azimuth scan mirror (ASM).
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 40 s.
Exposure
control
The exposure parameters for dcc05 are summarized in PET table Dark_Current_5.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcc05 low rate data they are listed in integration_time table 52.
Pixel size
n.a.



State ID 09
nad09
Scientific measurement Nadir
ILOS Description
see state ID 01
Scan see state ID 01
To adjust the view to a quasi telescopic close look the swath is set to 117 km by setting the scan speed to 2°/s. The basic position of the ESM is at -45.5°.
Swath The width is set to 'small', i.e. 116 km. Centering of the scan gives a start position of the forward scan of 65 km left of the subsatellite point (ESM angular position -49.35°) and a turnaround position of the forward scan of 51 km right of the subsatellite point (ESM angular position -41.65°).
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 01
The exposure parameters for nad09 are set to produce optimal signals for the orbital position
< -3° and > 183°. The definitions are summarised in PET table N1.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad09 low rate data they are listed in integration_time table 21.
Pixel size
(Ground pixel)
The ground pixel size is determined by the motion of the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 25 km × 0.6 km on ground - over the atmosphere during the integration time. The motion is a combined motion of the scan mirror and the orbital motion of the spacecraft. Since the integration time is diverse, and the angular speed for forward and flyback is different by a factor 4 the ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 26 km × 3.7 km.



State ID 10
nad10
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09
The exposure parameters for nad10 are set to produce optimal signals for the orbital position -3° to 0° and 180° to 183°. The definitions are summarised in PET table N2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad10 low rate data they are listed in integration_time table 22.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 26 km × 3.7 km.



State ID 11
nad11
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09
The exposure parameters for nad11 are set to produce optimal signals for the orbital position 0° to 16° and 164° to 180°. The definitions are summarised in PET table N3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad11 low rate data they are listed in integration_time table 23.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 26 km × 3.7 km.



State ID 12
nad12
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09
The exposure parameters for nad12 are set to produce optimal signals for the orbital position 16° to 26° and 154° to 164°. The definitions are summarised in PET table N4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad12 low rate data they are listed in integration_time table 24.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 26 km × 3.7 km.



State ID 13
nad13
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09
The exposure parameters for nad13 are set to produce optimal signals for the orbital position 26° to 36° and 144° to 154°. The definitions are summarised in PET table N5.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad13 low rate data they are listed in integration_time table 25.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 26 km × 3.6 km.



State ID 14
nad14
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09.
The exposure parameters for nad14 are set to produce optimal signals for the orbital position 36° to 70° and 110° to 144°. The definitions are summarised in PET table N6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad14 low rate data they are listed in integration_time table 26.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 27 km × 7.5 km.



State ID 15
nad15
Scientific measurement Nadir
ILOS Description
see state ID 09
Scan see state ID 09; speed 2°/s
Swath see state ID 09; width 116 km
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 forward and flyback scans. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 09.
The exposure parameters for nad15 are set to produce optimal signals for the orbital position 70° to 110°. The definitions are summarised in PET table N7.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad15 low rate data they are listed in integration_time table 27.
Pixel size
(Ground pixel)
see state ID 09
The ground pixel size varies between approx. 32 km × 29 km (along track × across track) and approx. 27 km × 7.5 km.



State ID 16
lwnd02
Monitoring NDF_Monitoring, ND Filter OUT
ILOS Description
For the purpose of monitoring the ND filter, the WLS is observed via the ESM under a ’non-optimal’ angle of 10.673° with the ND filter being ’OUT’.
In phase1 the position of the ESM is acquired and in measurement phase 2 the ESM points to the WLS under this angle (basic scan profile 13).
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 12 s.
Exposure
control
The exposure parameters for lwnd02 are summarised in PET table NDF_Monitoring. Note that channel 6 uses the Hot Mode (see Hot Mode table) with a PET of 7.2 ms.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For lwnd02 low rate data they are listed in integration_time table 48. The integration time given for channel 6 is the effective integration time which results from the Hot Mode. Readouts of channel 6 are obtained every 4 sec.
Pixel size
n.a.



State ID 17
ascd01
Calibration Sun_ASM_Diffuser_Calibation
ILOS Description
In state ID 17 sunlight is reflected onto the entrance slit of the spectrometer via the ASM diffuser which is mounted on the rear side of the ASM mirror. The Sun incidence angle onto the diffuser amounts to between 48.2°-65.5°. This is caused by the apparent motion of the Sun in azimuth (323.2°-326.5° for ascd01) and the required scan of the ASM of 14° during the measurement. The measurement starts when the Sun has reached an elevation of 22.5°, i.e. the angle of ‘reflection’ into the telescope is 22.5°. The aperture stop is set to ’large’ and the ND filter is ’OUT’.
In phase 1 the position of the ESM at 11.255° (corresponds to an altitude of 250 km, basic profile 9) and the position of the ASM are calculated (basic profile 4 without azimuth correction and H/W- constellation 1, ASM diffuser normal points towards +9° at the start of the state, i.e. ASM mirror normal = ASM angle amounts to 189°) and acquired. The ESM stays in this position fixed for the duration of the state. In the measurement phase 2 the ASM diffuser executes the scan of 14° thus changing the angle of incidence.
Scan A scan of 14° is performed. The scan speed amounts to 0.47°/s.
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for ascd01 are summarised in PET table Sun_ASM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For ascd01 high rate data they are listed in integration_time table 17.
Pixel size
n.a..



State ID 18
ascd02
Calibration Sun_ASM_Diffuser_Calibation
ILOS Description
see state ID 17
The state ascd02 is executed when the solar azimuth angle amounts to 326.5°-329.5°.
Scan see state ID 17; speed 0.47°/s
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for ascd02 are summarised in PET table Sun_ASM_diffuser
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For ascd02 high rate data they are listed in integration_time table 17
Pixel size
n.a.



State ID 19
ascd03
Calibration Sun_ASM_Diffuser_Calibation
ILOS Description
see state ID 17
The state ascd02 is executed when the solar azimuth angle amounts to 329.5°-332.5°.
Scan see state ID 17; speed 0.47°/s
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for ascd03 are summarised in PET table Sun_ASM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For ascd03 high rate data they are listed in integration_time table 17.
Pixel size
n.a..



State ID 20
ascd04
Calibration Sun_ASM_Diffuser_Calibation
ILOS Description
see state ID 17
The state ascd04 is executed when the solar azimuth angle amounts to 332.5°-335.5°.
Scan see state ID 17; speed 0.47°/s
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for ascd04 are summarised in PET table Sun_ASM_diffuser
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For ascd04 high rate data they are listed in integration_time table 17.
Pixel size
n.a.



State ID 21
ascd05
Calibration Sun_ASM_Diffuser_Calibation
ILOS Description
see state ID 17
The state ascd05 is executed when the solar azimuth angle amounts to 335.5°-337.9°.
Scan see state ID 17; speed 0.47°/s
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for ascd05 are summarised in PET table Sun_ASM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For ascd05 high rate data they are listed in integration_time table 17.
Pixel size n.a.



State ID 22
asad01
Monitoring Sun_ASM_Diffuser_Atmosphere
ILOS Description
In state asad01 the Sun is observed via the ASM diffuser while it rises through the atmosphere. Thus the atmosphere shall be used as a cut-off filter.
For the ASM diffuser position an average angle relative to the Sun (basic profile 10, as for state ID ascd02) is used. During the measurement the ASM diffuser executes a scan of 14.9° as for the states ID 17-21. Since the azimuth angle of the Sun varies over a year (323.2°-337.9°), the incidence angle onto the ASM diffuser changes between 46.2°-74.9°. The ESM remains fixed throughout the measurement. The aperture stop is set to ’large’ and the ND filter is ’OUT’.
The measurement starts when the Sun has reached an altitude of 17.2 km.
In phase 1 the pointing position of the ESM at an altitude of 17.2 km (corresponds to an ESM angle of -13.41°, basic profile 14) and the position of the ASM are calculated (basic profile 10 without azimuth correction and H/W- constellation 1, ASM diffuser normal points towards +7° at the start of the state, i.e. ASM mirror normal = ASM angle amounts to 187°) and acquired. The ESM stays in this position fixed for the duration of the state. In the measurement phase 2 the ASM diffuser executes the scan of 14° while the Sun is rising.
Scan A scan of 14.9° is performed. The scan speed amounts to 0.47°/s.
Swath n.a.
Measurement
duration
The duration of the measurement is set to 32 s.
Exposure
control
The exposure parameters for asad01 are summarised in PET table Sun_ASM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For asad01 high rate data they are listed in integration_time table 17.
Pixel size
n.a.



State ID 23
nad23
Scientific measurement Nadir_pointing
ILOS Description
In state ID 23 the earth atmosphere is observed pointing the line of sight (LOS) towards Nadir. To adjust the ILOS, SCIAMACHY uses for the measurement only the nadir/ elevation scan mirror (ESM).
By the orbital motion the atmospheric volume above the subsatellite point along the ground track is observed during the duration of the measurement. No scan motion of the ESM via a relative scan profile is invoked, since all factors are set to zero. The ESM is standing still in the basic position controlled by basic profile 1 yielding a position of -45.5°, corresponding to a slight shift in nadir (-z) for the ILOS.
The relative scan profile 2 is used only for the purpose of maintaining scanner control because of the applied Earth model correction throughout the measurement.
Scan no scan
Swath No swath is implied due to the stand still of the ESM. Principally the IFOV in dispersion direction of 0.045° ( 0.6 km ) determines the ‘swath’.
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive still sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
The exposure parameters for nad23 are set to produce optimal signals for the orbital position
< -3° and > 183°. The definitions are summarised in PET table N1.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad23 low rate data they are listed in integration_time table 21.
Pixel size
(Ground pixel)
The ground pixel size is determined by the motion of the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 25 km × 0.6 km on ground - over the atmosphere during the integration time. The motion of the IFOV is contrary to the ‘scanning’ nadir observations only caused by the orbital motion of the spacecraft and its pointing stability. Since the integration time is diverse, the ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 32 km × 0.6 km.



State ID 24
nad24
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive still sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad24 are set to produce optimal signals for the orbital position -3° to 0° and 180° to 183°. The definitions are summarised in PET table N2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad24 low rate data they are listed in integration_time table 22.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 32 km × 0.6 km.



State ID 25
nad25
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive still sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad24 are set to produce optimal signals for the orbital position 0° to 16° and 164° to 180°. The definitions are summarised in PET table N3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad25 low rate data they are listed in integration_time table 23.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32km × 1 km (along track × across track) and approx. 26 km × 0.6 km.



State ID 26
dcc04
Calibration Dark_Current_Calibration
ILOS Description
see state ID 08
ILOS pointing in flight direction to 250 km altitude above horizon.
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
see state ID 08
The exposure parameters for dcc04 are summarized in PET table Dark_Current_4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcc04 low rate data they are listed in integration_time table 51.
Pixel size
n.a.



State ID 27
elimb01
Scientific measurement Limb_Mesosphere
ILOS Description
In State 27 the earth mesosphere is observed centring the line of sight (LOS) towards the tangent to the earth horizon in the forward direction of the orbit (horizontal distance ca. 3290 km). Contrary to the other limb states, state ID 27 executes a sequence of measurements starting at high (150 km) and descending to low altitudes (approx. 80 km).
To adjust the ILOS, SCIAMACHY uses for the measurement the azimuth mirror (ASM) and the nadir/elevation scan mirror (ESM). No relative profile is applied to the ASM, i.e. no horizontal scan is performed. The basic position of the ASM is controlled by basic profile 2 yielding a position of -45°, corresponding to flight direction (-y) for the ILOS.
The ESM moves, with a timing as for the scanning limb observations, the ILOS a defined number of angular step towards -z direction. The basic starting position of the ESM is at 150 km (basic profile 5). The elevation step is controlled by relative profile 1, which adjusts the vertical step of the ESM in elimb01 to 0.0285° corresponding to a height resolution approx. 3 km. 23 elevation steps are program-med, i.e. yielding a stop altitude of approx. 80 km.
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 40.5 s.
Exposure
control
The exposure parameters for elimb01are set to produce optimal signals in the eclipse phase of the orbit. The definitions are summarised in PET table L6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For elimb01 low rate data they are listed in integration_time table 6.
Pixel size
(‘column’ pixel)
The atmospheric ‘column pixel’ size is determined by the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 103 km × 2.6 km at the distance of the tangent to the horizon. The orbital motion of the spacecraft during the integration time determines the column depth. Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 28
limb01
Scientific measurement Limb_short
ILOS Description
In State 28 the earth atmosphere is observed centering the line of sight (LOS) towards the tangent to the earth horizon in the forward direction of the orbit (horizontal distance of 3250 km for the mission extension orbit with 30 days / 431 orbits repeat cycle - in the nominal orbit with 35 days / 501 orbits repeat cycle the mean tangent length amounted to 3290 km). This tangent point shall coincide with the subsatellite point of the corresponding nadir observation at this horizontal distance.
To adjust the ILOS, SCIAMACHY uses for the measurement the azimuth mirror (ASM) and the nadir/elevation scan mirror (ESM). Instrument specific correction algorithms are applied to ASM accounting for the yaw steering of ENVISAT and for the Earth rotation during the time elapsed (approx. 450 s) between this measurement and the correlated nadir measurement. The basic position of the ESM, which shall be one elevation step below the horizon, is corrected for the varying horizontal height caused by the earth ellipsoid.
Scan The atmospheric volume at the horizon (subsatellite point of the corresponding nadir observation) is observed by directing the IFOV with the ASM. The scan motion of the ASM moves the ILOS in crosstrack direction. The basic position of the ASM is controlled by basic profile 2 yielding a position of -45°, corresponding to flight direction (-y) for the LOS. The motion of the ASM is controlled via relative scan profile 3, which is centered around the -y-direction. This profile produces for 1.5 seconds a relative motion (relative to -45° basic position) of constant angular velocity in positive direction and with the alternating inverted profile the ASM returns to the original angular position. The total angular motion of the ASM is approx. 8.5°, which is approx. 17° for the LOS. To account for the decline of the horizon a further correction is applied during this azimuth scan. Correction 3 maintains a constant distance above the horizon by adjusting the ESM position accordingly. Between the forward and reverse motion of the ASM, the ESM is controlled to move the ILOS a defined angular step towards zenith (+z), thus producing a meandering pattern for the ILOS path. The first measurement altitude for the ESM is right at the local earth horizon . The elevation step is controlled by relative profile 1, which adjusts the vertical step of the ESM in limb01 to 0.0570° (LOS) corresponding to a height resolution of approx. 3 km. 29 elevation steps and azimuth scans are programmed reaching to an altitude of about 93 km. These values refer to the ENVISAT orbit in the mission extension phase (30 days /431 orbits repeat cycle). In the nominal orbit each limb state executed 30 elevation steps and azimuth scans starting one elevation step below the horizon.
After the completion of the scans the ESM is moved by elevation basic profile 9 to an angle of about -11.255° (about 250 km above horizon) and the ASM to -45° (flight direction), which is the direction for the exo-atmospheric dark current measurement
Swath To adjust the earth coverage the azimuth swath is set to about 935 km by setting the ASM scan speed to 11.38°/s (LOS). This swath is identical to the one of the corresponding nadir observation. In the nominal orbit the swath width spanned - due to the larger orbit altitude - approx. 960 km with an ASM scan speed of 11.2°/s (LOS).
Measurement
duration
The duration of the measurement is 50.62 s (52.31 s in the nominal orbit), covering a total of 29 scans (30 scans in the nominal orbit) and the attached dark current measurement. A stretch of 3.03° of the orbit is passed during this time (3.12° in the nominal orbit).
Exposure
control
The exposure of the focal plane linear detector arrays (channels) is controlled by a subset of parameters setting the exposure times of the channels (6 plus 4 virtual) respectively the defined clusters and the corresponding co-adding factors. The exposure parameters for limb01 are set to produce optimal signals for the orbital position < -20°. The definitions are summarised in PET table L1.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb01 low rate data they are listed in integration_time table 1
Pixel size
(‘column’ pixel)
The atmospheric ‘column pixel’ size is determined by the scan motion in one layer (elevation step) of the atmosphere of the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° during the integration time. The IFOV corresponds to 102 km × 2.6 km at the distance of the tangent to the horizon. The orbital motion of the spacecraft during the integration time determines the column depth. Since the integration time is diverse, the column pixel size varies between approx. 933 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 233 km × 2.6 km. The values for the nominal orbit were 103 km × 2.6 km, 960 km × 3.6 km and approx. 240 km × 2.6 km.



State ID 29
limb02
Scientific measurement Limb_short
ILOS Description
see state ID 28
Scan see state ID 28; ASM: approx. 8.5° (mirror) corresponding to approx. 17° LOS; ESM: 30 steps
Swath see state ID 28; width 960 km
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28.
The exposure parameters for limb02 are set to produce optimal signals for the orbital position -20° to -12°. The definitions are summarised in PET table L2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb02 low rate data they are listed in integration_time table 2.
Pixel size
(‘column’ pixel)
see state ID 28
The column pixel size varies between approx. 1060 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 230 km × 2.6 km.



State ID 30
limb03
Scientific measurement Limb_short
ILOS Description
see state ID 28
Scan see state ID 28; ASM: approx. 8.5° (mirror) = approx. 17° LOS; ESM: 30 steps
Swath see state ID 28; width 960 km
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28.
The exposure parameters for limb03 are set to produce optimal signals for the orbital position -12° to 9° and 146° to 157°. The definitions are summarised in PET table L3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb03 low rate data they are listed in integration_time table 3.
Pixel size
(‘column’ pixel)
see state ID 28
The column pixel size varies between approx. 1060 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 230 km × 2.6 km.



State ID 31
limb04
Scientific measurement Limb_short
ILOS Description
see state ID 28
Scan see state ID 28; ASM: approx. 8.5° (mirror) = approx. 17° LOS; ESM: 30 steps
Swath see state ID 28; width 960 km
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28.
The exposure parameters for limb04 are set to produce optimal signals for the orbital position 9° to 20° and 125 ° to 146°. The definitions are summarised in PET table L4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb04 low rate data they are listed in integration_time table 4.
Pixel size
(‘column’ pixel)
see state ID 28
The column pixel size varies between approx. 1060 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 230 km × 2.6 km.



State ID 32
limb05
Scientific measurement Limb_short
ILOS Description
see state ID 28
Scan see state ID 28; ASM: approx. 8.5° (mirror) = approx. 17° LOS; ESM: 30 steps
Swath see state ID 28; width 960 km
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28.
The exposure parameters for limb05 are set to produce optimal signals for the orbital position 20° to 125°. The definitions are summarised in PET table L5.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb05 low rate data they are listed in integration_time table 5.
Pixel size
(‘column’ pixel)
see state ID 28
The column pixel size varies between approx. 1060 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 230 km × 2.6 km.



State ID 33
limb06
Scientific measurement Limb_short
ILOS Description
see state ID 28
Scan see state ID 28; ASM: approx. 8.5° (mirror) = approx. 17° LOS; ESM: 30 steps
Swath see state ID 28; width 960 km
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28.
The exposure parameters for limb06 are set to produce optimal signals for the orbital position
> 157°. The definitions are summarised in PET table L6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb06 low rate data they are listed in integration_time table 6.
Pixel size
(‘column’ pixel)
see state ID 28
The column pixel size varies between approx. 1060 km × 3.6 km (across track × height - incl. cycle step height error) and approx. 580 km × 2.6 km.



State ID 34
limb11
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 28
Scan see state ID 28
No relative profile is applied to the ASM. The basic position of the ASM is also controlled by basic profile 2 yielding a position of -45°, corresponding to flight direction (-y) for the ILOS. This position is maintained throughout the state, i.e. no horizontal scan is performed. ESM: 30 steps
Swath No swath is implemented. The ASM is standing still. The pixel dimension in azimuth is of a similar size (approx. 103 km ) as the swath of the corresponding nadir observation (120 km ).
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 28
The exposure parameters for limb11 are set to produce optimal signals for the orbital position 9° to 20° and 125° to 146°. The definitions are summarised in PET table L4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb11 low rate data they are listed in integration_time table 4.
Pixel size
(‘column’ pixel)
see state ID 28
The atmospheric ‘column pixel’ size is determined by the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 103 km × 2.6 km at the distance of the tangent to the horizon. The orbital motion of the spacecraft during the integration time determines the column depth. Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 35
limb08
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 34
Scan see state ID 34; no horizontal scan; ESM: 30 steps
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 34
The exposure parameters for limb08 are set to produce optimal signals for the orbital position
< -20°. The definitions are summarised in PET table L1.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb08 low rate data they are listed in integration_time table 1.
Pixel size
(‘column’ pixel)
see state ID 34
Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 36
limb09
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 34
Scan see state ID 34; no horizontal scan; ESM: 30 steps
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 34
The exposure parameters for limb09 are set to produce optimal signals for the orbital position -20° to -12°. The definitions are summarised in PET table L2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb09 low rate data they are listed in integration_time table 2.
Pixel size
(‘column’ pixel)
see state ID 34
Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 37
limb10
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 34
Scan see state ID ID 34; no horizontal scan; ESM: 30 steps
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 34
The exposure parameters for limb10 are set to produce optimal signals for the orbital position -12° to 157°. The definitions are summarised in PET table L3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb10 low rate data they are listed in integration_time table 3.
Pixel size
(‘column’ pixel)
see state ID 34
Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 38
lnad01
Monitoring Nadir_pointing_left
ILOS Description
In state ID 38 the earth atmosphere is observed pointing the line of sight (LOS) towards Nadir at the extreme left w.r.t. flight direction (approx. 30.5°). This measurement has the purpose to monitor the angle dependent degradation of the ESM mirror. To adjust the ILOS, SCIAMACHY uses for the measurement only the nadir/ elevation scan mirror (ESM).
The extreme left position is obtained by using basic profile 1, yielding a position of -45.5°, and a superimposed relative profile 5 which adds -15.95° to the ESM mirror normal. Once the extreme left position is acquired, the ESM stays in that configuration for the complete measurement phase.
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is 65 s. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
The exposure parameters for lnad01 are set to produce unsaturated signals throughout the orbit°. The definitions are summarised in PET table N7.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For lnad01 low rate data they are listed in integration_time table 27.
Pixel size
(Ground pixel)
The ground pixel size is determined by the motion of the Instantaneous Field of View (IFOV) of the instrument of 1.8° × 0.045° corresponding to approx. 25 km × 0.6 km on ground - over the atmosphere during one integration time. The motion of the IFOV is contrary to the ‘scanning’ nadir observations only caused by the orbital motion of the spacecraft and its pointing stability. Since the integration time is diverse, the ground pixel size varies between approx. 59 km × 1 km (along track × across track) and approx. 27 km × 0.6 km.



State ID 39
dcchm
Calibration Dark_Current_Calibration_Hot_Mode
ILOS Description
In state ID 39 the dark signal is measured for exposure times < 31.25 msec in channels 6-8 for the purpose of correcting WLS measurements.
In phase 1 the WLS-position of the ESM (10.523°) is acquired and in measurement phase 2 the ESM points to the WLS (basic scan profile 12).
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is 12 s. For the total duration of the measurement phase the WLS is off thus yielding only a dark current signal with state settings identical to those of the WLS state (ID 61).
Exposure
control
The exposure parameters for dcchm are summarised in PET table WLS.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcchm low rate data they are listed in integration_time table 55.
Pixel size
n.a.



State ID 40
limb13
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 34
Scan see state ID 34; no horizontal scan; ESM: 30 steps
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 34
The exposure parameters for limb13 are set to produce optimal signals for the orbital position
> 157°. The definitions are summarised in PET table L6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb13 low rate data they are listed in integration_time table 6.
Pixel size
(‘column’ pixel)
see state ID 34
Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 41
limb14
Scientific measurement Limb_short
(no swath)
ILOS Description
see state ID 34
Scan see state ID 34; no horizontal scan; ESM: 30 steps
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
see state ID 34
The exposure parameters for limb10 are set to produce optimal signals for the orbital position 20° to 125°. The definitions are summarised in PET table L5.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For limb12 low rate data they are listed in integration_time table 5.
Pixel size
(‘column’ pixel)
see state ID 34
Since the ASM stands still during a ‘scanning period’, the column pixel size has the size of the IFOV of approx. 103 km × 3.6 km (across track × height - incl. cycle step height error) also for different integration times.



State ID 42
nad26
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive ‘still’ sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad26 are set to produce optimal signals for the orbital position 16° to 26° and 154° to 164°. The definitions are summarised in PET table N4.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad26 low rate data they are listed in integration_time table 24.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 26 km × 0.6 km.



State ID 43
nad27
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive ‘still’ sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad27 are set to produce optimal signals for the orbital position 26° to 36° and 144° to 154°. The definitions are summarised in PET table N5
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad27 low rate data they are listed in integration_time table 25.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 26 km × 0.6 km.



State ID 44
nad28
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive ‘still’ sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad28 are set to produce optimal signals for the orbital position 36° to 70° and 110° to 144°. The definitions are summarised in PET table N6.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad28 low rate data they are listed in integration_time table 26.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 27 km × 0.6 km.



State ID 45
nad29
Scientific measurement Nadir_pointing
ILOS Description
see state ID 23
Scan see state ID 23; no scan
Swath see state ID 23; none
Measurement
duration
The duration of the measurement is set to 65 s, which results in 13 consecutive ‘still’ sequences. A stretch of 3.88° of the orbit is passed during this time.
Exposure
control
see state ID 23
The exposure parameters for nad29 are set to produce optimal signals for the orbital position 70° to 110°. The definitions are summarised in PET table N7.
Integration time The individual integration times are set by the exposure control (exposure time × co-adding factor). For nad29 low rate data they are listed in integration_time table 27.
Pixel size
(Ground pixel)
see state ID 23
The ground pixel size varies between approx. 32 km × 1 km (along track × across track) and approx. 27 km × 0.6 km.



State ID 46
dcc01
Calibration Dark_Current_Calibration
ILOS Description

see state ID 08
ILOS pointing in flight direction to 250 km altitude above horizon.

Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 10 s.
Exposure
control
The exposure parameters for dcc01 are summarized in PET table Dark_Current_1.
Integration time The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcc01 low rate data they are listed in integration_time table 45.
Pixel size n.a.



State ID 47
sos02
Scientific measurement
Calibration
SO&C_Scanning/
Pointing
ILOS Description
In state ID 47 the ILOS is directed towards the Sun during sunrise resp. the Sun whilst ascending. To adjust the ILOS, SCIAMACHY uses for the measurement the nadir/elevation scan mirror (ESM) and the azimuth scan mirror (ASM).
In the start phase the position of the ASM is calculated based on the position of the Sun defined in the START TIMELINE MCMD (correction 8 of basic scan profile 3 and relative profile 5). The position of the ESM is calculated (pointing to an altitude 17.2 km above the calculated point of sunrise). Both mirrors acquire their calculated position. In phase 2 ASM tracks the propagated Sun position, whereas ESM starts to scan ±0.33° around 17.2 km. This phase is determined to balance the effects of the atmospheric refraction on shape and motion of the Sun. At the end of this phase the centre of the Sun should coarsely coincide with the ILOS. In Phase 3 the Sun follower (SFS) takes over, acquires and tracks the Sun with the ASM, the ESM continues scanning while now following the rising target with the predicted velocity. In phase 4 the ESM maintains this scan motion. The ASM points to the Sun (correction 6). In phase 5 the Sun has passed the upper edge of the atmosphere. The ESM has stopped scanning and acquires also the Sun (correction 4 of basic profile 3 and relative profile 5). In the final phase (6) both mirrors track the Sun (correction 6 resp. correction 4).
Scan A scan of ±0.33° of the ILOS in elevation direction is implemented during phases 2-4, when ILOS is centered to 17.2 km or following the rising Sun. After completion of one scan the scanning direction is inverted for the subsequent scan. Scan duration is 2s each direction. Totally 16 scans are performed in phase 2, 2 scans in phase 3 and 14 in phase 4.
Swath n.a.
Measurement
duration
The initial phase of pointing to an altitude of 17.2 km above the location of sunrise has a duration of 32 s. The sun acquisition and pointing phase takes 4 s and the consecutive tracking/ scanning of the sun another 28 s. State ID 47 is concluded with a measurement of 2 s pointing to the Sun above the atmosphere. Total duration of sos02 is 66 s.
Exposure
control
The irradiation of the focal plane by the Sun is reduced by two mechanisms: An aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for sos02 are summarised in PET table Sun.
Integration time The individual integration times are set by the exposure control (exposure time × co-adding factor). For sos02 high rate data they are listed in integration_time table 32. A resolution of approx. 0.02° corresponding to 1.2 km at horizontal distance resp. 0.165° (10 km) is achieved.
Pixel size
n.a.



State ID 48
lwnd01
Monitoring NDF_Monitoring, ND Filter IN
ILOS Description
For the purpose of monitoring the ND filter, the WLS is observed via the ESM under a ’non-optimal’ angle of 10.673° with the ND filter being ’IN’.
In phase 1 the position of the ESM is acquired and in measurement phase 2 the ESM points to the WLS under this angle (basic scan profile 13).
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 12 s.
Exposure
control
The exposure parameters for lwnd01 are summarised in PET table NDF_Monitoring. Note that channel 6 uses the Hot Mode (see Hot Mode table) with a PET of 14.4 ms.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For lwnd01 low rate data they are listed in integration_time table 48. The integration time given for channel 6 is the effective integration time which results from the Hot Mode. Readouts of channel 6 are obtained every 4 sec.
Pixel size
n.a.



State ID 49
sos01
Scientific measurement
Calibration
SO&C_Scanning_Long_Duration
ILOS Description
see state ID 47.
In state ID 49 the ILOS is controlled in the first 3 phases with the same strategy as in ID 47.
Phase 4 has the same features as in ID 47 with ASM tracking the Sun and ESM following the track of the Sun with ESM basic profile 3 corrected with correction 8 whilst it scans. This phase continues above the atmosphere until the Sun has nearly reached the upper edge of the FOV of the limb baffle.
Scan A scan of ±0.33° of the ILOS in elevation direction is implemented during phases 1-4, when ILOS is centred to 17.2 km or following the rising Sun. After completion of a scan the scanning direction is inverted for the subsequent scan. Scan duration is 2s each direction. Totally 16 scans are performed in phase 2, 2 scans in phase 3 and 47 in phase 4.
Swath n.a.
Measurement
duration
The initial phase of pointing to an altitude of 17.2 km above the location of sunrise has a duration of 32 s. The Sun acquisition and pointing phase takes 4 s and the consecutive tracking/scanning of the sun another 94 s. Total duration of sos01 is 130 s.
Exposure
control
The irradiation of the focal plane by the Sun is reduced by two mechanisms: An aperture stop (prim.cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (prim.cmd ND FILTER IN). The exposure parameters for sos01 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For sos02 high rate data they are listed in integration_time table 32. A resolution of approx. 0.02° corresponding to 1.2 km at horizontal distance resp. 0.165° (10 km) is achieved.
Pixel size
n.a.



State ID 50
scs01
Calibration SO&C_Scanning (fast_sweep)
ILOS Description
In state ID 50 the Sun is used as a calibration source i.e. the solar position shall be well above the atmosphere. ASM and ESM are used to control the ILOS. Both mirrors shall follow the Sun track by means of basic profile 3. Since this profile is constructed to cover sunrise around an altitude of 17.2 km (see ID 47) it must be corrected for higher Sun elevation. Correction 8 uses the angular parameters of the Sun as they are contained in the MCMD START TIMELINE to calculate the correction terms for the two mirrors. These parameters are valid for the start of the measurement phase. Updates are performed with each relative profile.
In phase 1 the positions for both mirrors are calculated (correction 8) and acquired. In phase 2 both mirrors are following the corrected, propagated Sun trajectory and the ESM is in addition performing a scan (fast_sweep - relative profile 6) over the Sun.
Scan When the centre of the ILOS is following the rising Sun, scans over the Sun in elevation direction of approx. 2.72° (LOS) are performed. They are controlled by relative profile 6 (fast sweep), which produces a scan of 0.125 s duration in one direction and then holds this position for another 0.125 s. The scan speed (LOS) is 21.7°/s in the not accelerated segments of profile 6. The direction of the scan is inverted after each scan. In total 12 scans over the Sun of the type fast_sweep are performed during the measurement phase 2.
Swath n.a.
Measurement
duration
Total duration of scs01 is 3 s.
Exposure
control
The irradiation of the focal plane by the Sun is reduced by two mechanisms: An aperture stop (prim.cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (prim.cmd ND FILTER IN). The exposure parameters for scs01 are summarised in PET table Sun_Fast_Sweep. They are all set to 0.125 s.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For scs01 high rate data they are listed in integration_time table 36.
Pixel size
n.a.



State ID 51
sop01
Scientific measurement
Calibration
SO&C_Pointing
ILOS Description
In state ID 51 the ILOS is directed towards the Sun during sunrise resp. the Sun whilst ascending. To adjust the ILOS, SCIAMACHY uses for the measurement the nadir/elevation scan mirror (ESM) and the azimuth scan mirror (ASM). State ID 51 follows a similar strategy in the lower atmosphere as ID 47 and ID 49.
Phase 1 - start phase - with calculation/acquisition of sunrise position for ASM and 17.2 km height for ESM, phase 2 - ESM scanning at 17.2 km and ASM following Sun track- and phase 3 - Sun acquisition by ASM via SFS and ESM scanning - are identical to ID 47/49. In phase 4 ASM is sun pointing via SFS and ESM has stopped scanning and acquires the sun (correction 4). In Phase 5 ESM is now also pointing to the Sun (correction 6) as the ASM and both mirrors track the Sun centre till above the atmosphere.
Scan A scan of ±0.33° of the ILOS in elevation direction is implemented during phases 2 and 3, when theILOS is centred to 17.2 km scanning the rising Sun. Scan duration is 2s. After completion of a scan the scanning direction is inverted for the subsequent scan. Totally 24 scans over the Sun are performed during the phases 2 and 3.
Swath n.a.
Measurement
duration
The initial phase of pointing to an altitude of 17.2 km above the location of sunrise has a duration of 36 s. The Sun acquisition and pointing phase - only via ASM - takes 12 s and the consecutive tracking/ pointing to the Sun - now also ESM control via SFS - another 16 s. The final phase 5 - pointing to the Sun - provides several seconds of measurement time above the atmosphere. Total duration of sop01 is 64 s.
Exposure
control
The irradiation of the focal plane by the Sun is reduced by two mechanisms: An aperture stop (prim.cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (prim.cmd ND FILTER IN). The exposure parameters for sop01 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For sop01 high rate data they are listed in integration_time table 32.
Pixel size n.a.



State ID 52
escd01
Calibration Sun_ESM_Diffuser_Calibration
ND-Filter OUT
ILOS Description
In state ID 52 no image of the Sun is projected onto the entrance slit of the spectrometer. For calibration purposes the ESM diffuser is reflecting the sunlight into the telescope. This diffuser is a layer deposited on the rear side of the ESM. The angle between the SCIAMACHY optical axis and the diffuser normal shall amount to 15° to prevent vignetting from the scanner housing while the incident solar light has an angle of ‘reflection’ of 22.5° into the telescope.
In phase 1 the position of the ESM at 165° (backside of ESM under 15° inclination) and the position of the ASM are calculated (basic profile 6 with azimuth correction 8 and H/W- constellation 4) and acquired. The ESM stays in this position fixed for the duration of the state. In the measurement phase 2 ASM follows the motion of the Sun with the corrected rate from the START TIMELINE MCMD.
The timing of the state has to be planned in such a way, that the ascending Sun meets the requirement of 22.5° incidence angle at the start of the measurement phase.
Scan no scan
Swath n.a.
Measurement
duration
The measurement phase has a duration of 30s.
Exposure
control
escd01 is performed without additional reduction of the sunlight. The ND-filter is not used in escd 01 (primitive cmd ND FILTER OUT). The exposure parameters for escd01 are summarised in PET table Sun_ESM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For escd01 high rate data they are listed in integration_time table 40.
Pixel size n.a.



State ID 53
sscp02
Calibration Sub_Solar_Calibration_Pointing
ILOS Description
In state ID 53 the Sun is observed at high elevation through the sub_solar port (primitive cmd NADIR CAL WINDOW OPEN). In this configuration only the ESM can be used, therefore no capability exists to adjust the LOS in azimuth direction towards the Sun. To provide the required angular configuration the START TIMELINE MCMD for this state must be timed to fullfil the fixed angular correlation of the Sun position as related to the fixed IFOV in azimuth of SCIAMACHY in the sub_solar_window, which has a FOV of 1.72° (azimuth) × 14.78° (elevation) In azimuth the IFOV is further reduced by the small aperture used with solar observations (0.72°). The centerline of the aperture coincides with the centerline of the sub_solar_window.
In phase 1 the position of the ESM is calculated and acquired within the sub_solar_window applying correction 8 to basic profile 4 (sub_solar) for the actual position of the Sun contained in START TIMELINE MCMD. In phase 2 the ESM waits in this position for the Sun to come fully into the aperture. In phase 3 the ESM acquires the Sun with the SFS (correction 4) centering the slit (0.045°) on the Sun, during phase 4 the solar disk continues moving in azimuth direction through the aperture caused by the orbital motion. The ESM follows the solar track with correction 9, where the calculated Sun position is propagated with corrections derived from the SFS, whilst the Sun moves out of the aperture.
Scan no scan
Swath n.a.
Measurement
duration
The initial phase of pointing to the partially obscured sun has a duration of 7 s. The Sun acquisition phase take 6 s and the consecutive tracking/pointing to the vanishing sun another
9 s. Total duration of sscp02 is 22 s.
Exposure
control
The irradiation of the focal plane detectors (channels) by the Sun is reduced by two mechanisms: an aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for sscp02 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For sscp02 low rate data they are listed in integration_time table 31.
Pixel size n.a.



State ID 54
mos01
Calibration Moon_Scanning
ILOS Description
In state ID 54 the moon is used as a calibration source i.e. the lunar position shall be well above the atmosphere. ASM and ESM are used to control the ILOS. Both mirrors shall follow the track of the moon.
In phase 1 the predicted moon position and the resulting angular positions of both mirrors are calculated and the positions acquired. Correction 5 uses the angular data of the moon as they are contained in the MCMD START TIMELINE to calculate the correction terms for the two mirrors. These terms are valid for the start of phase 2. Updates are performed with each relative profile. In phase 2 both mirrors are acquiring the centre of the moon using the SFS with APERTURE STOP LARGE (phase type 1 and correction 5 - readout B). In phase 3 the ASM follows the moon in pointing mode stirred by the SFS loop and the ESM follows the track of the moon using the updated correction terms derived from correction 9 (improved tracking using AOCS), whilst it performs nominal scans over the moon.
Scan A scan of ±0.33° of the ILOS in elevation direction is implemented during phase 3, when ILOS is centred to the moon and following his track. Scan duration is 2 s each direction. The scan direction is inverted after each scan. 5 nominal scans over the moon are performed.
Swath n.a.
Measurement
duration
The acquisition/pointing phase 2 of mos01 takes 2 s. The scanning phase 3 takes 10 s. Total duration of mos01 is 12 s.
Exposure
control
The exposure parameters for mos01 are summarised in PET table Moon.
Integration
time
For mos01 low rate data they are listed in integration_time table 47.
Pixel size n.a.



State ID 55
lmt01
Scientific measurement Limb_Mesosphere_Thermosphere
ILOS Description

In State 55 the earth mesosphere and lower thermosphere is observed centring the line of sight (LOS) towards the tangent to the earth horizon in the forward direction of the orbit (horizontal distance ca. 3290 km). This state is similar to the nominal limb states except that the scan occurs from 150 km downwards to low altitudes (approx. 60 km) and the exposure times are adjusted to the lower light levels.
To adjust the ILOS, SCIAMACHY uses for the measurement the azimuth mirror (ASM) and the nadir/elevation scan mirror (ESM). An instrument specific correction algorithm is applied to the basic position of the ESM accounting for the varying horizontal height caused by the earth ellipsoid.

Scan The atmospheric volume at the horizon (subsatellite point of the corresponding nadir observation) is observed by directing the IFOV with the ASM. The scan motion of the ASM moves the ILOS in crosstrack direction. The basic position of the ASM is controlled by basic profile 2 yielding a position of -45°, corresponding to flight direction (-y) for the LOS. The motion of the ASM is controlled via relative scan profile 3, which is centered around the -y-direction. This profile produces for 1.5 seconds a relative motion (relative to -45° basic position) of constant angular velocity in positive direction and with the alternating inverted profile the ASM returns to the original angular position. The total angular motion of the ASM is approx. 8.5°, which is approx. 17° for the LOS. To account for the decline of the horizon a further correction is applied during this azimuth scan. Correction 3 maintains a constant distance above the horizon by adjusting the ESM position accordingly. Between the forward and reverse motion of the ASM, the ESM is controlled to move the ILOS a defined angular step towards nadir (-z), thus producing a meandering pattern for the ILOS path. The first measurement position for the ESM occurs at an elevation of 150 km. The elevation step is controlled by relative profile 1, which adjusts the vertical step of the ESM in limb01 to 0.0570° (LOS) corresponding to a height resolution of approx. 3 km. 30 elevation steps and azimuth scans are programmed reaching to an altitude of about 60 km.
After the completion of the scans the ESM is moved by elevation basic profile 3 to an angle of about -10.000° (about 350 km above horizon) and the ASM to -45° (flight direction), which is the direction for the exo-atmospheric dark current measurement
Swath n.a.
Measurement
duration
The duration of the measurement is 52.31 s, covering a total of 30 scans and the attached dark current measurement. A stretch of 3.12° of the orbit is passed during this time.
Exposure
control
The exposure parameters for lmt01 are summarised in PET table LMT.
Integration
time
For lmt01 low rate data they are listed in integration_time table 10.
Pixel size n.a.



State ID 56
mop01
Scientific measurement
Calibration
MO&C_Pointing
ILOS Description
In state ID 56 the moon is used to measure the atmosphere in occultation.
Contrary to ID 51 - SO&C_Pointing - the measurement starts, when the moon crosses the height of 17.2 km above the horizon. This requires exact tuning of the start of the timeline, since in pointing mode the dimensions of the spectrometer slit determine the observed area.
In phase 1 the predicted moon position and the resulting angular position of ASM and ESM are calculated (correction 8 of basic profile 3 resp. 14) and acquired. The moon should have a height of 17.2 km above the horizon. In phase 2 both mirrors are tracking the centre of the moon using AOCS information. In phase 3 the ASM and ESM acquire the moon with the SFS (correction 5 - readout B). This occurs at an altitude of about 70 km. Phase 4 follows the moon up to the top of the atmosphere, now with both the pointing ASM and the ESM being controlled via the SFS (correction 7).
Scan no scan
Swath n.a.
Measurement
duration
The duration of the initial pointing phase (phase 2) without SFS control amounts to 16 s. The acquisition/pointing phase 3 of mop01 takes 2 s. The tracking phase 4 takes 22 s. Total duration of mop01 is 40 s.
Exposure
control
The exposure parameters for mop01 are summarised in PET table Moon.
Integration
time
For mop01 low rate data they are listed in integration_time table 47.
Pixel size n.a.



State ID 57
mop02
Scientific measurement
Calibration
Moon_Pointing_Long_Duration
ILOS Description
In state ID 57 the moon is used to measure the atmosphere in occultation and to get, in addition, calibration measurements above the atmosphere.
The strategy is a copy of state ID 56 but the moon pointing phase 4 is extended until the moon nearly reaches the upper edge of the TCFOV of the limb baffle.
Scan no scan
Swath n.a.
Measurement
duration
The duration of the initial pointing phase (phase 2) without SFS control amounts to 16 s. The acquisition/pointing phase 3 of mop01 takes 2 s. The tracking phase 4 takes 110 s. Total duration of mop02 is 128 s.
Exposure
control
The exposure parameters for mop02 are summarised in PET table Moon.
Integration
time
For mop02 low rate data they are listed in integration_time table 47.
Pixel size n.a.



State ID 58
sscp01
Calibration Sub_Solar_Calibration_Pointing/
Scanning
ILOS Description
In state ID 58 the Sun is observed at high elevation similar to state ID 53.
In phase 1 the position of the ESM in the sub_solar_window is calculated with basic profile 4 applying correction 8 for the actual position of the Sun contained in START TIMELINE MCMD and acquired. In phase 2 the ESM follows the propagated track of the Sun waiting for her to come fully into the aperture due to the orbital motion. In phase 3 the ESM acquires the Sun with the SFS (correction 4) centering the slit (0.045°) on the Sun and during this phase the solar disk moves in azimuth direction through the aperture caused by the orbital motion while being tracked by the ESM via SFS. In phase 4 the ESM performs 2 nominal scans over the Sun (relative profile 4) while the centre of the scan is maintained on the middle of the Sun using correction 9, where the calculated Sun position is propagated with the corrections derived from the SFS. In phase 5 the Sun moves out of the aperture being tracked with the now standing still ESM (correction 9).
Scan A scan of ±0.33° of the ILOS in elevation direction centred on the Sun is implemented during phase 4. Scan duration is 2 s. Two nominal scans are performed.
Swath n.a.
Measurement
duration
The initial phase of pointing to the partially obscured sun has a duration of 7 s. The Sun acquisition and pointing phase takes 2 s, the scan phase 5 takes 4 s and the consecutive tracking/pointing to the vanishing Sun another 9 s. Total duration of sscp01 is 22 s.
Exposure
control
The irradiation of the focal plane detectors (channels) by the Sun is reduced by two mechanisms: An aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for sscp01 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For sscp01 low rate data they are listed in integration_time table 31.
Pixel size n.a.



State ID 59
lsc01
Calibration Spectral_Lamp_Calibration
ILOS Description
In state ID 59 SCIAMACHY´s spectral lamp is used as a spectral line source for wavelength calibration. The ESM is used to project the spectral light into the telescope.
In phase 1 the SLS position of the ESM (9.768°) is acquired and in measurement phase 2 the ESM points to the SLS (basic scan profile 10).
In this state a longer duration for cooldown is required.
Scan no scan
Swath n.a.
Measurement
duration
Measurement duration of lsc01 is 12 s.
Exposure
control
The exposure parameters for lsc01 are summarised in PET table SLS.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For lsc01 low rate data they are listed in integration_time table 53.
Pixel size n.a.



State ID 60
sscs01
Calibration Sub_Solar_Calibration_Scanning
(fast_sweep)
ILOS Description
In state ID 60 the Sun is observed at high elevation similar to state ID 53.
In phase 1 the ESM is positioned with basic profile 4 in the sub_solar_window applying correction 8 for the actual position of the Sun contained in START TIMELINE MCMD. In phase 2 the basic position of the ESM follows the propagated track of the Sun centre (correction 8) and performs additionally fast_sweeps over the Sun, which moves through the aperture in azimuth direction caused by the orbital motion.
Scan When the centre of the ILOS is following in elevation direction the Sun, scans over the Sun in elevation direction of ca. 2.72° are performed. They are controlled by relative profile 6 (fast_sweep), which produces a scan of 0.125 s duration in one direction and then holds this position for another 0.125 s. The scan speed (LOS) is 21.7°/s in the not accelerated segments of profile 6. The direction of the scan is inverted after each scan. Totally 88 scans over the Sun of the type fast_sweep are performed during the measurement phase.
Swath n.a.
Measurement
duration
The measurement phase (scanning fast_sweep of the part time obscured Sun) has a duration of 22 s.
Exposure
control
The irradiation of the focal plane detectors (channels) by the sun is reduced by two mechanisms: An aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for sscs01 are summarised in PET table Sun_Fast_Sweep. The effective exposure of all pixels to the Sun is 31.25 msec, since due to the fast_ sweep motion of the ILOS the IFOV scans over the complete Sun within this time.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For sscs01 low rate data they are listed in integration_time table 35.
Pixel size n.a.



State ID 61
lwc01
Calibration White_Lamp_Calibration
ILOS Description
In state ID 61 SCIAMACHY´s white lamp is used as a light source for radiometric calibration. The ESM is used to project the white light into the telescope.
In phase 1 the WLS position of the ESM (10.523°) is acquired and in measurement phase 2 the ESM points to the WLS (basic scan profile 12).
In this state a longer duration for cooldown is required.
Scan no scan
Swath n.a.
Measurement
duration
Measurement duration of lwc01 is 12 s.
Exposure
control
The exposure parameters for lwc01 are summarised in PET table WLS.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For lwc01 low rate data they are listed in integration_time table 55.
Pixel size n.a.



State ID 62
escd02
Calibration Sun_ESM_Diffuser_Calibration
ND-Filter IN
ILOS Description
see state ID 52
The ESM diffuser position is at 165° (backside of ESM under 15° inclination), the ASM is following the motion of the Sun.
The timing of the state has to be planned in such a way, that the ascending
Sun meets the requirement of 22.5° incidence angle at the start of the measurement phase. .
Scan no scan
Swath n.a.
Measurement
duration
The measurement phase has a duration of 30 s.
Exposure
control
escd02 is performed with additional reduction of the sun light compared to ID 52. The ND-filter is used in escd02 (primitive cmd ND FILTER IN). The exposure parameters for escd02 are summarised in PET table Sun_ESM_diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For escd02 high rate data they are listed in integration_time table 40.
Pixel size n.a.



State ID 63
dcc02
Calibration Dark_Current_Calibration
ILOS Description
see state ID 08
ILOS pointing in flight direction to 250 km altitude above horizon
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 30 s.
Exposure
control
The exposure parameters for dcc02 are summarized in PET table Dark_Current_2.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcc02 low rate data they are listed in integration_time table 49.
Pixel size n.a.



State ID 64
nmep01
Calibration Sun_Nadir/Elevation_Mirror
Calibration_Pointing
ILOS Description
In state ID 64 the Sun is used as calibration source. ID 64 uses the extra_mirror for a second reflection of the ESM (H/W-constellation 5). The correction algorithms used take account of the doubled mirror deflection. Basic profile 8 used for ESM and ASM also accounts for the extra_mirror.
In phase 1 the calculation of the predicted Sun position and the resulting angular positions by both mirrors are performed. Correction 4 uses the angular data of the Sun as they are contained in the MCMD START TIMELINE to calculate the correction terms for the twomirrors. These terms are valid for the start of phase 2. The positions are acquired by ASM and ESM. In phase 2 both mirrors are acquiring the centre of the Sun using the SFS (phase type 1 and correction 4 - readout A). In phase 3 the ILOS is following the Sun in pointing mode stirred by the SFS loop.
Scan no scan
Swath n.a.
Measurement
duration
The pointing phases 2 plus 3 of nmep01 take 4 s.
Exposure
control
The irradiation of the focal plane by the sun is reduced by two mechanisms: An aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for nmep01 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For nmep01 high rate data they are listed in integration_time table 32.
Pixel size n.a.



State ID 65
adc01
Calibration ADC_Calibration & Scanner_Maintenance
ILOS Description
In State ID 65 the Analogue Digital Converter is calibrated. At the same time the maintenance of the scanners is performed, which require one full revolution of each scanner per orbit to ensure full performance. To synchronise source sequence counter measurement data packets are produced. This is no scientific measurement state but a maintenance state, which is executed each orbit in nominal operations conditions.
Scan Scanner motions (ASM & ESM) for one full revolution within the state duration are implemented.
Swath n.a.
Measurement
duration
The duration of the measurement is set to 20 s.
Exposure
control
The exposure parameters for adc01 are summarized in PET table ADC_Cal.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For adc01 low rate data they are listed in integration_time table 43.
Pixel size n.a.



State ID 66
nmes02
Calibration Sun_Nadir/Elevation_Mirror
Calibration_Scanning
ILOS Description
In state ID 66 the Sun is used as calibration source. It uses the same constellation as ID 64, but scans the Sun via the double reflection from the ESM by means of the extra_mirror.
In phase 1 the calculation of the predicted Sun position and the resulting angular positions of both mirrors are performed. Correction 4 uses the angular data of the Sun as they are contained in the MCMD START TIMELINE to calculate the correction terms for the two mirrors. These terms are valid for the start of phase 2. The positions are acquired by the ASM and ESM. In phase 2 both mirrors are acquiring the centre of the Sun using the SFS (phase type 1 and correction 4 - readout A). In phase 3 the ASM is following the Sun in pointing mode stirred by the SFS loop and the ESM performs nominal scans over the Sun following her track using correction 9 (SFS-corrected propagated Sun positions).
Scan In phase 3 the nominal_scan of ±0.33° of the ILOS in elevation direction centred on the Sun is implemented. Because of the double reflection off the ESM, its angular motion is halved as compared to the standard nominal_scan. Scan duration is 2 s. The scanning direction is inverted for each subsequent scan. In total 5 scans are performed.
Swath n.a.
Measurement
duration
The pointing phase 2 of nmes02 takes 1 s and the scanning phase 3 takes 10 s. Total duration is 11 s.
Exposure
control
The irradiation of the focal plane by the sun is reduced by two mechanisms: An aperture stop (prim.cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for nmes02 are summarised in PET table Sun.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For nmes02 high rate data they are listed in integration_time table 32.
Pixel size n.a.



State ID 67
dcc03
Calibration Dark_Current_Calibration
ILOS Description
see state ID 08
ILOS pointing in flight direction to 250 km altitude above horizon.
Scan no scan
Swath n.a.
Measurement
duration
The duration of the measurement is set to 80 s.
Exposure
control
The exposure parameters for dcc03 are summarized in PET table Dark_Current_3.
Integration
time
The individual integration times are set by the exposure control (exposure time × co-adding factor). For dcc03 low rate data they are listed in integration_time table 50.
Pixel size n.a.



State ID 68
nmes01
Calibration Sun_Nadir/Elevation_Mirror
Calibration_Scanning (fast_sweep)
ILOS Description
In state ID 68 the Sun is used as calibration source. It uses the same constellation as ID 64 and ID 66, but the scan of the Sun via the extra_mirror is of the type fast_sweep.
In phase 1 the calculation of the predicted Sun position and the resulting angular positions of both mirrors are performed. Correction 8 uses the angular data of the Sun as they are contained in the MCMD START TIMELINE to calculate the correction terms for the two mirrors. These terms are valid for the start of phase 2. The positions are acquired by the ASM and ESM. In phase 2 the ASM follows the propagated track of the Sun. The same does the ESM and performs additionally the fast_sweeps over the solar disk whilst it follows the Sun centre.
Scan In phase 2 scans of the type fast_sweep over the sun of ca. 2.72° are performed. They are controlled by relative profile 6 (fast_sweep), which produces a scan of 0.125 s duration in one direction. The scan speed (LOS) is 21.7°/s in the not accelerated segments of profile 6. The direction of the scan is inverted after each scan. Because of the double reflection off the ESM its angular motion of the mirror is halved as compared to the standard fast_sweep. In total 12 scans are performed.
Swath n.a.
Measurement
duration
The scanning phase 2 takes 3 s.
Exposure
control
The irradiation of the focal plate by the sun is reduced by two mechanisms: An aperture stop (primitive cmd APERTURE STOP SMALL) reduces the collecting area of the telescope and a neutral density filter reduces the light flux (primitive cmd ND FILTER IN). The exposure parameters for nmes01 are summarised in PET table Sun_Fast_Sweep. The effective exposure of all pixels to the Sun is 31.25 msec, since due to the fast_ sweep motion of the ILOS the IFOV scans over the complete Sun within this time.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For nmes01 high rate data they are listed in integration_time table 36.
Pixel size n.a.



State ID 69
lsd01
Calibration Spectral_Lamp_ESM_Diffuser_Monitoring
ILOS Description
In state ID 69 SCIAMACHY´s spectral lamp is used as a spectral line source to calibrate the spectral characteristics of SCIAMACHY´s ESM diffuser. The diffuser is deposited on the backside of the ESM.
In phase 1 the position of the ESM (190.2°) is acquired and in measurement phase 2 the ESM diffuser normal points to a direction between SLS and WLS (basic scan profile 11).
In this state a longer duration for cooldown is required.
Scan no scan
Swath n.a.
Measurement
duration
Measurement duration of lsd01 is 80 s.
Exposure
control
The exposure parameters for lsd01 are summarised in PET table SLS_Diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For lsd01 low rate data they are listed in integration_time table 57.
Pixel size n.a.



State ID 70
lwd01
Calibration White_Lamp_ESM_Diffuser_Monitoring
ILOS Description
In state ID 70 SCIAMACHY ´s white lamp is used as a light source to calibrate the radiometric characteristics of SCIAMACHY ´s ESM diffuser. The diffuser is deposited on the backside of the ESM.
In phase 1 the position of the ESM (190.2°) is acquired and in measurement phase 2 the ESM diffuser normal points to a direction between SLS and WLS (basic scan profile 11).
In this state a longer duration for cooldown is required.
Scan no scan
Swath n.a.
Measurement
duration
Measurement duration of lwd01 is 80 s.
Exposure
control
The exposure parameters for lwd01 are summarised in PET table WLS_Diffuser.
Integration
time
The individual integration times are set by the exposure control (exposure time × coadding factor). For lwd01 low rate data they are listed in integration_time table 59.
Pixel size n.a.



Page generated 20 February 2002; last update: 11 January 2011