Getting Ready for PICARD Helioseismology Program – Decembre NICE THE PICARD PAYLOAD DATA CENTER Grégory PRADELS

2 PAYLOAD PROGRAMMING PLAN How is elaborated the measurement plan ? KERGUELEN KOUROU HARTEBEESHOEK KIRUNA TOULOUSE BRUSSELS Satellite control center Payload data center PICARD SATELITE Data users

3 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.

4 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

5 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 image f)dark current limb g)2 windowed images h)small dark current image a) b) a) c) d) e) f) g)h)

6 SOLAR OBSERVATIONS SEQUENCE Ascending node local time:6h00 Altitude:725 km Inclination:98.29° Eccentricity:1.04 x 10-3 Helio sequence Non helio measurements 14,4 85,86% Helio measurements rate

7 Ascending node local time:6h00 Altitude: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 + ND NA a i Xs Ys Zs N S

8 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 Number of minutes used by other activities Helio measurements rate with respect to the by default helio sequence By default helio sequence: One helio macropixel per minute One helio limb per 2 minutes 78,93% Total helio measurements rate (including other activities) with respect to the by default helio sequence

9 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)

10 MISSION SCIENTIFIC PRODUCTS  SODISM  Level 0, 1, 2A + Quicklook L0, L1  Fits format  L0/L1/L2A ~ files/day  Volume ~ 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

11 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, nm  PSPT’s images  5 full images at 409.4, 607.1, nm

12 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

13 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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15 WANT TO KNOW MORE ?  PAPER  The PICARD Payload Data Centre, G. Pradels et al. SPACEOPS 2008, Heildelberg, Germany Ask by  WEB SITES  

16 ECLIPS DURATION vs ALTITUDE

17 ATMOSPHERIC DISTRUBANCES