Getting Ready for PICARD Helioseismology Program – Decembre 2008 - NICE

THE PICARD PAYLOAD DATA CENTER

Grégory PRADELS

gregory.pradels@cnes.fr

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PAYLOAD PROGRAMMING PLAN

How is elaborated the measurement plan ?

KERGUELEN

KOUROU

HARTEBEESHOEK

KIRUNA

TOULOUSE

BRUSSELS

Satellite control center

Payload data center

PICARDSATELITE

Data users

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WHAT IS A PAYLOAD DATA CENTER ?

A PROCESSING CENTER TO Create the measurements plan of all the instruments, Process all the raw telemetry, Create the mission products (L0 L2A), Control the instrumental parameters,

A DATA BANK TO Collect the data from various location (CNES, CNRS, PSPT, etc), Disseminate the data to the users (automatic or on demand service), Archive the data (short and long term archive),

AN OPERATIONNAL CENTER TO Verify the measurement plan Take care of the mission data production, Communicate about the mission operations.

So it’s the interface between data users and the instruments.

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THE PICARD PAYLOAD

SODISM Cassegrain telescope,

SOVAP Differential radiometer + bolometric

sensor,

PREMOS 2 absolute radiometers + 3 photometers,

ONBOARD PROCESSING Downlink limited to 325 Mbytes/s Necessity to process the data

SODISM

PREMOS

SOVAP

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a) full image (2048x2048)b) solar limb (4) with markers (1-3)c) macropixels (8x8)d) flat-field (with internal lens)e) full dark current imagef) dark current limbg) 2 windowed imagesh) small dark current image

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SOLAR OBSERVATIONS SEQUENCE

orbit = 100 minutesday = 14 orbits

years = 365,25 daysmission = 3 years

minute orbit day year missionHelio macropixels (535 nm) 1Helio limb (535 nm) 0,5

minute orbit day year missionHelio macropixels (535 nm) 1 100 1 440 525 960 1 577 880Helio limb (535 nm) 0,5 50 720 262 980 788 940

Ascending node local time : 6h00Altitude : 725 km Inclination : 98.29° Eccentricity : 1.04 x 10-3

Helio sequence

minute orbit day year missionWide limbs (215, 393, 535, 607, 782 nm) 10 144 52 596 157 788Full images (215, 393, 535, 607, 782 nm) 5 72 26 298 78 894Dark current limb 4 58 21 038 63 115Dark current full image 1 365 1 096Flatfield (215, 535, 607, 782 nm) 1 365 1 096

Total 301 989

Non helio measurements

14,4

85,86%Rate

Helio macropixels (535 nm) 77,47%Helio limb (535 nm) 93,22%

Helio measurements rate

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Ascending node local time : 6h00Altitude : 725 km Inclination (i) : 98.29° Eccentricity : 1.04 x 10-3

DISTURBING PERIODS

ECLIPSES 0 to 25 minutes per orbit October to February

ATMOSPHERIC DISTURBANCES 0 to 8 minutes per orbit 1 week per year (october)

SCALE FACTOR DETERMINATION Stellar pointing 66 minutes Once per 3 months

OPTICAL CALIBRATION 12 rotations of 30 deg 936 to 1200 minutes Once a month

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ND

NA

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XsYs

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BILAN

Mean helio sequence duration (out of the eclipse period):- sequence of one macropixels per min ~ 20 min - sequence of one limb per 2 min ~ 1 month

minute orbit day year missionEclipse 22 032 66 096Atmospheric disturbances 806 2 419Scale factor calibration 264 792Optical calibration 12 552 37 656

Total 106 963

Number of minutes used by other activities

RateHelio macropixels (535 nm) 80,86%Helio limb (535 nm) 100,00%

Helio measurements rate with respect to the by default helio sequence

By default helio sequence:One helio macropixel per minuteOne helio limb per 2 minutes

RateHelio macropixels (535 nm) 77,47%Helio limb (535 nm) 93,22%

78,93%

Total helio measurements rate (including other activities) with respect to the by default helio sequence

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TELECOMMANDS & TELEMETRY

TELECOMMANDS MANAGEMENT Automatic process, Triggered twice a week at the Payload Data Centre, Uses orbital prediction and scientific requirements, Produce the measurement plan for the coming 10 days, Checked by an operator, Send by the Satellite Control Centre.

TELEMETRY MANAGEMENT Automatically collected on the CNES server (secured FTP server), Collected continuously (every day) Telemetries are processed at Day+1 to create Level 0 data Level 0 data are processed at Day+2 / Day+3 to create Level 1-2 data Disseminate on payload data centre server (secured FTP server)

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MISSION SCIENTIFIC PRODUCTS

SODISM Level 0, 1, 2A + Quicklook L0, L1 Fits format L0/L1/L2A ~ 4 400 files/day Volume ~ 2 000 Mbyte/day

SOVAP Level 0, 1, 2A + Quicklook L1 ASCII and fits format L0/L1/L2A : 5 files/day

PREMOS Level 0, 1, 2A ASCII format L0/L1/L2A : 11 files/day

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ON GROUND SCIENTIFIC PRODUCTS

OCA’s images Limbs at 393, 535, 607, 782 nm Full image at 393 nm Number function of the observation possibility

LESIA’s images (393 nm) 3 full images at 393.3, 393.4 nm

PSPT’s images 5 full images at 409.4, 607.1, 393.4 nm

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OTHER PRODUCTS

ORBITAL DATA Satellite ephemerids

– With respect to the Sun and the Earth– Inertial reference frame (J2000)

Satellite attitude– Quaternion or Euler angles

Satellite orbital events

Sun ephemerids

Characteristics : ASCII format, 1 file/day

HOUSEKEEPING Instrument housekeeping data Satellite housekeeping data

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HOW TO COLLECT THE PICARD DATA

AUTOMATIC DEPOSIT New data are automatically recorded on the FTP server, FTP server are available for authorised groups, Security = login/pwd (no data coding), Data are compressed (zip files) Old data will be erased (period to be defined)

ON DEMANDE SERVICE A search engine will be available on the Payload Data Centre web site, Criteria = date, data level, instrument, etc From the results page you will be able to :

– Download the files,– Show the images/data (ASCII file, fits header),

Possibility to draw a graph : y=f(x) Services available for authorised people

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WANT TO KNOW MORE ?

PAPER The PICARD Payload Data Centre, G. Pradels et al.SPACEOPS 2008, Heildelberg, Germany

Ask by email : gregory.pradles@cnes.fr

WEB SITES http://smsc.cnes.fr/PICARD/Fr/GP_mission.htm http://www.busoc.be/fr/operationnel/picard.htm

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ECLIPS DURATION vs ALTITUDE

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ATMOSPHERIC DISTRUBANCES