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.