| MAJ_ICU | To monitor the radiometric performances of MAJIS using VISNIR and IR sources Specifically, there are several goals
A) tracking the evolution of the actual levels (before subtracting for CDS) in the digital dynamics (0-65535 at 100 kHz, 0-4095 at 1 MHz). Such an evolution could lead to adjust an offset which can be selected by TC (4 settings) so as to avoid reaching digital saturation for the read image before analog saturation.
B) tracking the evolution of the dark current and cosmetics (new hot / dead pixels)
C) tracking the evolution of the overall photometric response as a function of the signal (needed for the pipeline)
Pointing: MAJIS scan mirror oriented towards the ICU (8.5°)
Satellite orientation: Deep space
Duration: 10min | MAJIS |
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| MAJ_JUP_LIMB_SLEW | The scan the atmosphere of Jupiter over the limb up to 3000k is performed with a specific slew of the S/C
Individual lines are largely overlapped to provide actual supersampling (x 10) in the spatial domain and allow sub-pixel resolution by deconvolution.
Typically, we have cubes of about 300 lines by 50 pixels (~7500 km)
Pointing type:
OFF-NADIR (nominal pointing position over the Jupiter limb), continuous tracking (‘track tangent limb’)
satellite orientation:LIMB TANGENT (MAJIS slit tangent to the limb), very slow s/c slew to get oversampling (10 lines corresponding to one pixel IFOV)
Duration: 55 min for each cube (300 lines) | MAJIS |
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| MAJ_JUP_HIGH_FREQ_MONITORING | The observing type is designed to study the evolution of atmospheric features at high temporal frequency as well as to map specific atmospheric features at regional scale.
Scanning of features on the Jovian disc, on dayside as well as on nightside, with limited latitudinal coverage.
MAJIS will acquire one or more several “subcubes” with a limited number of lines (about between 64 and 160)
Duration: between 84 and 315 s for each cube, assuming 2.1 s per line | MAJIS |
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| MAJ_JUP_LIMB_SCAN | The MAJIS pointing mirror is used to scan the atmosphere of Jupiter over the limb up to 1500km. Exposure times are optimized for weak limb emissions.
The scan mirror step of 1/10 MAJIS IFOV shall constrain the spatial sampling provides a spatial supersampling adequate to reconstruct, by deconvolution, the signal vertical profile at sub-pixel scale.
Observations consists in sets of max. 8 cubes at different latitudes, around the limb of the planet.
Duration: Typically 20 min for each cube (110 lines), assuming 11 s per line | MAJIS |
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| MAJ_GCO5000_GLOBAL | Systematic mapping performed with cross-track binning by 4 during circular phase (~120 days)
3 km/pixel, 300x300 km swaths, spatial binning x 4.
Pointing: YS, Nadir
Satellite orientation: MAJIS slit at a slant with the ground track except at the equator
Duration: 4H per orbit (one cube: 6 min) | MAJIS |
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| MAJ_JUP_EVENT_MONITORING | Study of the evolution of unusual phenomena in Jupiter atmosphere, especially in their zonal evolution MAJIS will acquire several “subcubes” with limited number of lines (about 80) as follows:
1. a series of sub-cubes (from 1 to 4) is acquired with the scan mirror to get the coverage of a limited latitude region at all longitudes on the visible side of the planet. Satellite is re-pointed before acquiring each sub-cube
2. the series at previous point is repeated at fixed time intervals (in the order of 1 h, TBC) to monitor the temporal evolution.
Pointing type: YS, Series of OFF-NADIR pointings (‘off-nadir scan mode’)
satellite orientation: HORIZONTAL
Duration:
160 sec for each sub-cube.
Time between series defines actual temporal sampling and is variable (zero data rate here).
Total duration about 5 h (1/2 of rotation period) | MAJIS |
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| MAJ_BORESIGHT_ALIGNEMENT | Star sequence for geometrical calibration.
A star is initially pointed using the MAJIS boresight, then MAJIS is operated with the scan mechanism at high resolution (1/3 of IFOV) over 18 lines centered in the star. Then this operation is successively observed after 4 S/C repointings of 1.5° around X and Y.
Pointing : inertial
Satellite orientation: S/C pointing the star and MAJIS scans
Duration: 18 to 180 sec per position (5 positions in total)+ stabilization time for repointing not taken into account | MAJIS |
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| MAJ_Amalthea | S/C pointing Amalthea preferentially near maximal elongation of (2.54 R_J), 2 hemispheres, MAJIS spatial windowing (16 rows)
pointing: OFF-NADIR, S/C pointing Amalthea at 2.54 R_J while maintaining horizontal orientation of MAJIS slit
satellite orientation: Maintaining horizontal orientation of MAJIS slit, MAJIS scan mode activated for vertical sampling centered on the satellite (10 lines)
Duration: 100 sec for one hemisphere | MAJIS |
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| MAJ_MainRING _PhaseCurve | Observations of the main rings at various phase angles (N angles), one ansae (always the same), 20 vertical lines
Pointing: S/C pointing ring plane at 1.8 R_J (extremity of main rings)
Satellite orientation: OFF-NADIR, Ring plane while maintaining horizontal orientation of MAJIS slit, MAJIS scan mode activated for vertical sampling centered on the rings (20 lines)
Duration: 200 sec for one observations at a given phase angle | MAJIS |
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| MAJ_MainRING _LowPhase | Observations of the main rings (2 ansa), no tracking of azimuthal structure, 20 vertical lines
pointing: OFF-NADIR, S/C pointing centered on the extremity of main rings, S/C depointing required for the two ansa
Satellite orientation: Maintaining the MAJIS slit parallel to radial axis of main rings, MAJIS scan mode activated for vertical sampling centered on the rings (20 vertical lines)
Duration:400 sec (excluding the S/C repointing to the other ansae) | MAJIS |
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| MAJ_MainRING _HighPhase | Observations of the main rings (2 ansa) at high phase (forward scattering light), no tracking of azimuthal structure, no spatial binning to increase spatial resolution.
Pointing: OFF-NADIR, S/C pointing centered on the extremity of main rings, S/C depointing required for the two ansa
Satellite orientation: Maintaining the MAJIS slit parallel to radial axis of main rings, MAJIS scan mode activated for vertical sampling (20 vertical lines) centered on the rings
Duration: 400 sec (excluding the S/C repointing to the other ansae) | MAJIS |
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| MAJ_JUP_DISK_SLEW | Observations of Jupiter clouds and spectroscopy of minor gases.
Scanning the instrument slit over Jovian disk (vertical direction) by means of the S/C slew. aims to cover the entire equatorial region (-30°:+30°)
Pointing: OFF_NADIR, CONTINUOUS SLEW (« continuous S/C scan »)
Satellite orientation: HORIZONTAL
Duration: 20 min per cube | MAJIS |
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| MAJ_JUP_DISK_SCAN | Observations of Jupiter clouds and spectroscopy of minor gases.
Scanning the instrument slit over Jovian disk (vertical direction) by means of internal pointing mirror, both dayside and nightside. Aims to cover at least the entire equatorial region (-30°:+30°) during low inclination phases and the polar regions during high inclination phase.
Duration: typically 20min/cube, max 30 min/cube, assuming 2.1 s per line | MAJIS |
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| MAJ_GCO500_HR | Observations in true push-broom of specific targets on the surface using motion compensation with the scanner
30 km cross-track x 8.7 km along-track @ 75 m/pixel
30 km cross-track x 17.4 km along-track @ 150 m/pixel (spatial binning x2)
Pointing: Nadir pointing, NYS ( ‘motion compensation PB’)
Satellite orientation: MAJIS slit perpendicular to the ground-track
Duration: One acquisition: 60 sec; switch-on procedure: 10 minutes (TBC) | MAJIS |
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| MAJ_GCO5000_AURORA | Observations at auroral latitudes (30-35° N-S), at least in the dawn and dusk sides of Jovian magnetosphere.
Mapping at spatial resolution of about 1 km using the MAJIS scan
Pointing: S/C limb; no requirements on the slit orientation
Saletllite orientation: Off-nadir orientation | MAJIS |
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| MAJ_Ring_Occultation | Observation of a star occulted by the rings
Scan windowing of 9 lines centered on the star (1 scan step = 1/3 MAJIS IFOV) possible
Pointing: Inertial. For each occultation, transit of TBD min
Satellite orientation: Inertial pointing of the S/C towards the position of the star to maintain MAJIS slit fixed on it. These occultation observations need to be consolidated in the future (star atlas, signal, Tint, S/C inertial capabilities). Scan mirror can be used to mitigate APE drift | MAJIS |
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| MAJ_SAT_DISK_SCAN | Observation of a distant satellite dayside or nightside surface. Satellite offset required for pointing then disk coverage is achieved using the internal pointing mirror scanning in the Y (N-S) direction.
Pointing: NADIR-P with possible offset around Y, YS, MAJIS scan (‘Nadir scan’).
Satellite orientation: MAJIS slit perpendicular to the ground-track
Duration: 30min | MAJIS |
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| MAJ_JovianRING_MOSAIC | Mosaicking the 2 ring ansa from 90000 to 230000 km. 3 overlapping cubes of 20 vertical lines performed by the scanner (or S/Cslew if compatible with JANUS). This requires re-pointing between individual cubes.
Pointing: OFF-NADIR, S/C pointing projected ring plane, S/C depointing required for the two ansa
Satellite orientation: Maintaining the horizontal orientation of MAJIS slit, MAJIS scan mode activated for vertical sampling (20 vertical lines) centered on the rings, S/C depointing required for mosaicking each ansa (3 overlapping cubes to perform a radial mosaic of one ansa of the rings with radial distance from 90000 to 230000 km)
Duration: 1200 sec (excluding the S/C repointings) | MAJIS |
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| MAJ_GCO500_LIMB | Mapping of selected areas on the dayside limb at resolutions of about 300 m at different latitudes (~30° in lat/lon from the nadir) to study variability of the exospheric processes (sputtering, photodissociation, sublimation). MAJIS scanning at different latitudes of the diurnal limb; a minimum of 3 (north,equat,south) x 2 (dawn, dusk) positions.
Pointing: S/C limb tracking at locations where the slit is tangent to the limb
satellite orientation: Off-nadir orientation, Slit tangent to the limb
Duration: 600 sec per cube | MAJIS |
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| MAJ_JUP_STELLAR_OCC | MAJIS will acquire several “subcubes” (number depends upon planet's speed over the sky) around the (fixed) star position, at different angular distances between the star and the planet's limb during the ingress/egress.
Each sub-cube spans over several lines (around 6, less if S/C capability allows it) to compensate for possible pointing inaccuracies.
Bright far moons can be used instead of stars as sources to decrease the repetition integration (and therefore spatial sampling) as the orbital velocity ranges from ~ 5 km/s at apojove to ~ 13 km/s at perijove
satellite orientation: LIMB TANGENT (preferred, otherwise VERTICAL), to minimize straylight
duration:
About 10min
66 sec (max) for each subcube. Time interval between sub-cubes as small as possible for better vertical coverage. Total number of cubes depends upon relative angular speed between star and limb. | MAJIS |
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| MAJ_SERVICE | MAJIS in service MODE (1 or 2 channels with FPE/FPA off + AUX w/o loads)
SERVICE Mode as soon as one or two channels are switched ON (PE and AUX)
From SERVICE, it is possible to return to SAFE mode or to change the status of MAJIS to DIAG2, DIAG3 or SCIENCE
Duration: less than 10min | MAJIS |
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| MAJ_GCO5000_LIMB | Latitudinal scanning of the diurnal limb at 1 km at different latitudes; study of the variability of the exospheric processes (sputtering, photodissociation, sublimation). Observe polar (north/south) and equatorial latitudes ; perform long-term and high-temporal-resolution monitoring.
Pointing: S/C limb tracking at locations where the slit is tangent to the limb
Satellite orientation: Off-nadir orientation, Slit tangent to the limb
Duration: 600sec | MAJIS |
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| MAJ_JUP_AURORAL_MAPPING | Jupiter Auroral Mapping
Scanning of the instrument slit over Jovian polar regions, from polar limb to approx. 50°N/S latitudes, with exposure times optimized for weak auroral emissions.
Note: similar to MAJIS_JUP_DISK_SCAN but for high latitudes during high inclination phase
Duration: typically, 40 min (200 lines <-> typical size of latitudes where polar ovals are observed) | MAJIS |
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| MAJ_SAFE | Initiated after ASW loading
All channels are off and no PE HK are generated. Only ME HK are generated (only DPU ON)
From SAFE it is possible 1) to switch OFF MAJIS, 2) to change the status of MAJIS to DIAG1 or SERVICE mode
Duration: less than 5min | MAJIS |
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| MAJ_FLYBY_HR | High resolution pubshbroom flyby observations of satellite dayside surfaces bracketing closest approach. Satellite offsets around Y (off-track pointing) axis during or prior to observation allow near-nadir pointing of specific regions. Motion compensation or MAJIS scan is achieved using the MAJIS internal pointing mirror depending on the S/C speed and distance. Binning can be applied may be required near C/A.
Pointing: NYS, NADIR or OFF_NADIR after offset around Y (‘motion compensation PB’).
Satellite orientation: MAJIS slit across track, Satellite offsets around Y (off-track pointing) axis possible.
Duration: 20 to 130 sec | MAJIS |
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| MAJ_FLYBY_MEDRES | Flyby observations of the satellite surface with vertical (N-S) slews or MAJIS scan providing medium spatial resolution (e.g.resolution from 3 km to 1 km/pixel for Ganymede). Perform when the S/C moves slowly from approach YS phase to PB phase and during PB phase.
Pointing: NYS, NADIR or OFF_NADIR after offset around Y ( ‘motion compensation PB’).
Satellite orientation: MAJIS slit across track. Satellite offsets around Y (off-track pointing) axis or around X axis (for slew).
Duration: a few minutes maximum | MAJIS |
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| MAJ_SAT_DISK_SLEW | Flyby observations of the satellite surface with vertical (N-S) slews across track, during yaw-steering phase. One or two slews (pole to pole) necessary to complete dayside coverage. Satellite offset around Y-axis (E-W) before each observation, then satellite offsets around X axis (N-S) between each slit acquisition.
Pointing: NADIR Pointing, YS, S/C scan (slew) with offset around Y (‘mosaic mode’ tbc). MAJIS slit perpendicular to the ground-track.
Satellite orientation: MAJIS slit perpendicular to the ground-track
Duration: 30 min | MAJIS |
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| MAJ_SAT_LIMB_SCAN | Flyby observations of the satellite dayside or nightside limbs with vertical (N-S) slews across track, during yaw-steering phase. Satellite offsets to limb around Y-axis (E-W) before each observation, then satellite offsets around X axis (N-S) between each slit acquisition or continuous slew pointing.
Pointing: S/C slew scan centred a limb ( ‘Limb slew scan mode’).
Satelliteo orientation: Slit tangent to the limb
Duration: 60min | MAJIS |
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| MAJ_GEO5000 | During elliptical phase (~15 days before and after circular phase), mapping of selected areas (~40) at intermediate to high resolutions: 50 to <750 m/pix, bridging the gap in resolution between systematic mapping (MAJIS_GCO5000_global) and GCO ROIs (MAJIS_GCO500_HR).
Pointing: YS, NADIR
satellite orientation: MAJIS slit at a slant with the ground track except at the equator
Duration: from 35 min to 4H (Table 8 from budget report v2.1) | MAJIS |
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| MAJ_GCO5000_REGIONAL | During circular phase (~120 days), regional mapping of the surface of Ganymede, bridging the gap in resolution between systematic global mapping and HR ROI's observed at GCO-500.
750 m/pix (no spatial binning), 300x300 km swaths
Pointing type: YS, NADIR
Satellite orientation: MAJIS slit at a slant with the ground track except at the equator
Duration: 6min | MAJIS |
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| MAJ_SAT_LIMB_TRACK | Continuous stare observation of a satellite limb during flyby using inertial pointing from satellite, dayside or nightside. Additional offsets within limb by means of internal pointing mirror. Scanning with MAJIS internal mirror. (--> ‘track limb’).
Pointing: S/C limb tracking (‘track limb’)
satellite otientation: SLIT tangent to the limb (slit not aligned with S/C motion)
Duration: 60min | MAJIS |
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| MAJ_STANDBY | After switch-on of MAJIS, the Boot SW automatically starts, and performs the primary boot from the PROM (Init fugitive BSW mode).
After processor modules initialization, the Boot software goes to STANDBY mode. By default, the ASW Image0 (stored in MRAM0 = ASM0) is autonomously loaded after a timeout of 30 seconds. MAJIS then enters into ASW init Mode and then into SAFE mode.
In STANDBY Mode, all channels are off, and only DPU HK SID1 are received.
MAJIS needs to be maintained in STANDBY mode using the TC(17,1) in the following cases :
- upload (using service 6) of new ASW images (or CUSW, or firmware) into MRAM: FCP-MAJ-070 describes the maintenance process.
- upload a new BROWSE Table FCP-MAJ-060 into MRAM
- select ASW Image1 and then start ASW Image 1 instead of teh default ASW Image0. FCP-MAJ-062
- any other update of MRAM using service 6 | MAJIS |
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| MAJ_JUP_DISK_MOSAIC | A series of several MAJIS_JUP_DISK_SCAN or MAJIS_JUP_DISK_SLEW
Spacecraft has to be re-pointed between individual acquisitions.
POinting type: YS, NADIR with offset around Y (‘ nadir offset MAJIS scan’’)
satellite orientation: HORIZONTAL (preferred)
Duration:
3 x (scan-duration + turnaround Y duration). Scan duration from 20 to 40 min depending on the distance from Jupiter. Turnaround ~50 min | MAJIS |
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