EPHIN L-0 Data Pool ===================== Ephin data set consists of the following number of files per day number per day filetype data type contents ------------------------------------------------------------------------------ 1 binary Science : instrument status, counter channel, coincidence channel, histogram, PHA 1 ASCII SFDU : Science data generation information ------------------------------------------------------------------------------ 1 binary Housekeeping : Ephin housekeeping information 1 ASCII SFDU : HSK data generation information ------------------------------------------------------------------------------ 3 binary Housekeeping : S/C housekeeping information 3 ASCII SFDU : HSK data generation information ------------------------------------------------------------------------------ 1 binary Attitude : S/C attitude data (CDF) 1 ASCII SFDU : Attitude data generation information ------------------------------------------------------------------------------ 1 binary Orbit : S/C orbit data (CDF) 1 ASCII SFDU : Orbit data generation information ------------------------------------------------------------------------------ 1 ASCII Command History : Telemetry command listings 1 ASCII SFDU : Att data generation information ------------------------------------------------------------------------------ EPHIN Science Data File Format =============================== general construct: A. data set file header : 48 bytes B. data block : n data source packets C. QAC block : - 4 bytes QAC list length in bytes - m * 14 bytes QAC capsules A. science data set file header: byte address bit address contents --------------------------------------------------------- 1 & 2 0 : 5 spare 6 : 15 Spacecraft ID --------------------------------------------------------- 3 : 11 Spacecraft Clock PB5 format first source packet --------------------------------------------------------- 12 spare --------------------------------------------------------- 13 : 21 Spacecraft Clock PB5 format last source packet --------------------------------------------------------- 22 spare --------------------------------------------------------- 23 : 26 number of source packets in file --------------------------------------------------------- 27 : 43 spare --------------------------------------------------------- 44 number of QAC lists in file --------------------------------------------------------- 45 : 48 offset in bytes from end of file header to QAC list --------------------------------------------------------- B. science data block (data source packet format) -consists of 8 packets of 174 bytes length packet no byte address contents --------------------------------------------------------- 1 1: 6 packet header 1:2 packet id 3:4 packet counter 0..7 5:6 packet lenght 174 7: 12 time tag (EPOCH) 13:174 EPHIN data block 1.st part --------------------------------------------------------- 2:7 1: 6 packet header 1:2 packet id 3:4 packet counter 0..7 5:6 packet lenght 174 7: 12 time tag (EPOCH) 13:174 EPHIN data block 1.st part --------------------------------------------------------- 8 1: 6 packet header 1:2 packet id 3:4 packet counter 0..7 5:6 packet lenght 174 7: 12 time tag (EPOCH) 13:168 EPHIN data block 1.st part 169:174 spare --------------------------------------------------------- C. QAC block - QAC list lenght in bytes (4 bytes) - m * QAC 14-bytes-capsules: byte address lenght contents --------------------------------------------------------- 1: 4 4 position of errored packet in data set (counted from last bit of file header) --------------------------------------------------------- 5: 6 2 spare --------------------------------------------------------- 7 1 error type flag --------------------------------------------------------- 8:12 5 spare --------------------------------------------------------- 13:14 2 packet fill start location --------------------------------------------------------- EPHIN Housekeeping Data File Format =================================== general construct: A. data set file header : 48 bytes B. data block : n data source packets C. QAC block : - 4 bytes QAC list length in bytes - m * 14 bytes QAC capsules B. housekeeping data block (data source packet format) -consists of 1 packet of 50 bytes length packet no byte address contents --------------------------------------------------------- 1 1: 6 packet header 1:2 packet id 3:6 spare 7: 12 time tag (EPOCH) 13: 34 EIO HK (22 bytes) 35: 50 EPHIN HK (16 bytes) --------------------------------------------------------- EPHIN Spacecraft Housekeeping Data File Format =============================================== general construct: A. data set file header : 48 bytes B. data block : n data source packets C. QAC block : - 4 bytes QAC list length in bytes - m * 14 bytes QAC capsules B. spacecraft housekeeping data block format -consists of 1 packet of 18 bytes length packet no byte address contents --------------------------------------------------------- 1 1: 6 packet header 1:2 packet id 3:6 spare 7: 12 time tag (EPOCH) 13 EPHIN S/C powered thermistor 14: 18 S/C temps. --------------------------------------------------------- Time tag format (EPOCH) The time tag is thought as an epoch, based on 1958 January 1. 4 of the 6 bytes are used as coarse time, counted in seconds, 2 bytes are used as fine time, counted in 2**-11 seconds (11 bits used, 5 spare). ----------------------------------------------------------------- |bit |bit |bit |bit |bit |bit | | |31 .. 24 |23 .. 16 |15 .. 8 |7 .. 0 |-1 .. -8 |-9 .. -11 |XXXXX| -------------------------------------|--------------------------- coarse time | fine time