Document title: Format description for IMP-8 GME CNTS data TRF entry: b49065.txt in NSSDC's controlled digital document library, Aug. 1999. Document text follows: ---------------------- [File obtained Oct. 5, 1998 from http://voycrs.gsfc.nasa.gov/lo/imp8/cnts.html.] ---------------------------------------------------------------------------- -------------------------------------- IMP-8 COUNTS FILE FORMAT -------------------------------------- IMP-8 counts file consists data records of one 4-day interval, with the last record indicated by a negative interval number. Data records are fixed-blocked by a factor of 3. Physical records are 3564 bytes in length. Logical records are 1188 bytes(297 words) in length and represent one album of data. ---------------------------------------------------------------------------- WORD CONTENT 1 Universal time at start of album(tenths of seconds of year) 2 S/C clock at start of album right justified(low order 6 bits zero) 3 Pseudo-sequence count, negative at 400 BPS, positive at 1600 BPS 4 Halfword 1 Day of year Halfword 2 Perigee count 5 Milliseconds of day 6 Longitude geocentric(degrees) 7 Latitude " 8 Longitude geomagnetic(degrees) 9 Latitude " 10 Ro(earth radii) (C.U.L.) 11 Radial distance from center of earth(km) 12 GSEx Satellite position in geocentric solar ecliptic coordinates(km) 13 GSEy " " 14 GSEz " " 15 GSMx Satellite position in geocentric magnetospheric coordinates(km) 16 GsMy " " 17 GSMz " " 18 GEIx Sun position in geocentric equatorial inertial coordinates(AU) 19 GEIy " " 20 GEIz " " 21 L McIlwain parameter(earth radii) 22 B Magnetic field strength(gamma) 23 Lsep Satellite earth sun angle(degrees) 24 Year of recording 25 Halfword 1 Data quality flag Halfword 2 Time quality flag 26 Halfword 1 Number of 4-day period(negative, last record of this period) Halfword 2 Day of next perigee 27 Milliseconds of day of next perigee 28 Right ascension spin vector in celestial inertial coordinates(deg.) 29 Declination " " 30 Halfword 1 Year Time of orbit data Halfword 2 Day of year 31 Milliseconds of day 32-35 Spare ---------------------------------------------------------------------------- WORD TYPE OF EVENT ACCUM.# LEVELS 36-43 (8) DI.E.-F.-G MED-R1 0,2,4,6,8,10,12,14 44-51 (8) DI.E.F.-G MED-R2 0,2,4,6,8,10,12,14 52-55 (4) DI.-D2.E.-F.-G MED-R3 0,4,8,12 56-59 (4) DI.-(DI+EI)l.E.-F.-G MED-R3 2,6,10,14 60-63 (4) ID1 MED-R4 0,4,8,12 64-67 (4) ID2 MED-R4 2,6,10,14 68-71 (4) DI.(DII+EII)R.E.-F.-G MED-R5 1,5,9,13 72-75 (4) DI.E.F MED-R5 3,7,11,15 76-79 (4) DI.(DI+EI)2.-(DII+EII)R.E.F.-G MED-R6 0,4,8,12 80-83 (4) DI.(DII+EII)R.E.F.-G MED-R6 2,6,10,14 84-87 (4) DI MED-R7 1,5,9,13 88-91 (4) E MED-R7 3,7,11,l5 92-95 (4) F MED-R8 0,4,8,12 96-99 (4) G MED-R8 2,6,10,14 100-103 (4) DI.(DI+EI)l.E.-F.-G MED-R9 1,5,9,13 104-107 (4) (DI+EI)2.E.-F.-G MED-R9 3,7,11,15 108-115 (8) (A+B)l.B.-C LED-R1 1,3,5,7,9,11,13,15 116-123 (8) A.B.-C LED-R2 0,2,4,6,8,10,12,14 124 Al LED-R3 0 125 (A+B)l.-B.-C LED-R3 2 126 B LED-R3 4 127 (A&B)2.A.B.-C LED-R3 6 128 (A&B)2.A.-B.-C LED-R3 8 129 Al.B LED-R3 10 130 A1.-B.-C LED-R3 12 131 C LED-R3 14 132-179 (48) VLET PHA DATA: 16 3-word groups(one per snapshot) as follows: Word 1: DI(VLET-R1) Sign bit contains event type: 0 = DI.DII.Sum(2)D.-F 1 = DI.DII.Sum(1)D.-F Word 2: DII(VLET-R2) Sign bit indicates undetermined event type if one Word 3: E(VLET-R3) If any of the three values was padded or negative as a result of offset subtraction for a snapshot, all three values for that snapshot will be set to -1 180-181 (2) DI 4 VLET-R4 1,9 182-183 (2) DI 3 VLET-R4 2,10 184-185 (2) DI 2 VLET-R4 3,11 186-187 (2) DI 1 VLET-R4 4,12 188-189 (2) F VLET-R4 5,13 190-191 (2) E VLET-R4 6,14 192-193 (2) DII VLET-R4 7,15 194-195 (2) DI VLET-R4 0,8 196-203 (8) DI.DII.Sum(1)D.-F VLET-R5 Even 204-211 (8) DI.DII.Sum(2)D.-F VLET-R5 Odd ---------------------------------------------------------------------------- WORD TYPE OF EVENT 212 Sectored data information Halfword 1: OA/TM Slave flag 0 IF OA Slave mode 1 IF TM Slave mode during any portion of album Halfword 2: Analog transmitter ON/OFF flag 0 = off 1 = On during any portion of album 213-220 (8) MED sectors 1-8, Page 0 DI.E.F.-G 221-228 (8) MED sectors 1-8, Page 1 DI.-D2.E.-F.-G 229-230 (8) MED sectors 1-8, Page 2 (DI+EI)1.E.-F.-G 237-244 (8) MED sectors 1-8, Page 3 DI.-(DI+EI)1.E.-F.-G 245 Halfword 1: 20 = 1 if a corrected LED sectored rate was < 0 in Page 0 21 = 1 if a corrected LED sectored rate was < 0 in Page 3 Halfword 2: 20 = 1 if a corrected sun time was used for Page 0 21 = 1 if a corrected sun time was used for Page 3 = 4 if no OA data was available. No corrections made 246-253 (8) LED sectors 1-8, Page 0 Al.-B.-C 254-261 (8) VLET sectors 1-8, Page 1 DI.DII.-F 262-269 (8) VLET sectors 1-8, Page 2 DI.DII.Sum(1)D.-F 270-277 (8) LED sectors 1-8, Page 3 A1.B.-C 278 DP a2-17 (VLET event type) Byte 1: 2 redundant readouts for each of snapshots 0-3 of page 0 Byte 2: Same as above for Page 1 Byte 3: Same as above for Page 2 Byte 4: Same as above for Page 3 (Note: These correspond to the sign bits of the DI words of 132-179. If the two redundant readouts are different for any snapshot, the sign bit for the DII word of that snapshot will be set to 1 and the sign bit of DI will be set to 1) 279 Halfword 1 APP-6 Leakage current, Page 0 Halfword 2 " " " , Page 1 280 Halfword 1 APP-6 Leakage current, Page 2 Halfword 2 " " " , Page 3 281 Halfword 1 APP-36 MED temp, Page 1 Halfword 2 " " " , Page 3 ---------------------------------------------------------------------------- WORD CONTENT 282 Sun time 283 Earth width Page 0 284 Earth time (S.S. 1) 285 Spin period 286-289 (4) Same as above Page 1 290-293 (4) Same as above Page 2 294-297 (4) Same as above Page 3 ---------------------------------------------------------------------------- NON-SECTORED RATES The trend check for each rate will be right-justified in the lst byte of the word. The last 3 bytes will contain the rate value. If the rate is padded, the entire 4 byte word will contain l's (-l). SECTORED RATES The trend check for each sectored rate will be performed on the sum of the sector values, and the resulting flag will be stored in the lst byte of that word for SECTOR 1 in the same manner as for non-sectored rates.