NGA GNSS Division SP3 Format

SP3 Format Description

NGA products use the format finalized by the National Geodetic Survey. The SP3 format provide ephemeris
data in either position (P) mode or velocity (V) modes. The SP3 format is precise to 1 mm and 1 picosecond.
-4 -4
Velocity, when included, is precise to 10 mm/sec and 10 picoseconds/s.

The following is the format for the "enhanced" SP3:

1 2 3 4 5 6
123456789012345678901234567890123456789012345678901234567890

1 #aV2012 10 1 0 0 0.00000000 288 DD+AD WGS84 FIT NGA

2 ## 1708 86400.00000000 300.00000000 56201 0.0000000000000
3 + 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
4 + 18 19 20 21 22 23 25 26 27 28 29 30 31 32 0 0 0
5 + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
6 + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
7 + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
8 ++ 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
9 ++ 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 0 0
10 ++ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
11 ++ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
12 ++ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
13 %c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
14 %c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
15 %f 0.0000000 0.000000000 0.00000000000 0.000000000000000
16 %f 0.0000000 0.000000000 0.00000000000 0.000000000000000
17 %i 0 0 0 0 0 0 0 0 0
18 %i 0 0 0 0 0 0 0 0 0
19 /* NGA, ST. LOUIS,MO.
20 /* EPHEMERIS COMPUTED FROM 1 DAYS OF DATA
21 /* EPOCHA SMOOTHER
22 /* CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
Date last modified: February 20, 2020 Approved for public release, 17-808.
23 * 2012 10 1 0 0 0.00000000
24 P 1 -1677.901589 16285.584053 -20920.350325 275.849218
25 V 1 -25096.728698 8665.572021 8818.525202 0.015870
26 P 2 20801.130436 -14268.541598 7587.240521 404.556632
27 V 2 10280.136019 -147.845949 -29536.235333 0.011634
28 . . . .
29 . . . .
30 . . . .
31 . . . .
32 . . . .
33 . . . .
34 * 2012 10 1 23 55 0.00000000
35 P 1 -1545.870613 16240.292187 -20966.016107 275.985617
36 V 1 -25177.862925 8604.994335 8581.662169 0.015774
37 . . . .
38 . . . .
39 . . . .
40 . . . .
41 . . . .
42 . . . .
43 P 32 -143.412125 18718.631715 -18837.924362 -493.864143
44 V 32 -18157.215193 -16024.551820 -15137.882157 -0.039374
45 EOF

Line and Column Descriptions

Line 1: ('#aV',i4,4i3,f12.8,6x,'96 DD+AD WGS84 FIT NGA')
Column Description Allowed or Sample value
1 Symbol #
2 Version Identifier a
3 Position/Velocity Mode Flag P or V
4-7 Year Start 2012
8 Unused
9-10 Month Start 10
11 Unused
12-13 Day of Month Start 1
14 Unused
15-16 Hour Start 0
17 Unused
18-19 Minute Start 0
20 Unused

Date last modified: February 20, 2020 Approved for public release, 17-808.
Column Description Allowed or Sample value
21-31 Second Start 0.00000000
32 Unused
33-39 Number of Epochs 288
40 Unused
41-45 Data Used DD+AD
46 Unused
47-51 Coordinate System WGS84
52 Unused
53-55 Orbit Type FIT
56 Unused
57-60 Agency NGA

Line 2: ('##',i5,f16.8,f15.8,i6,f16.13)
Column Description Allowed or Sample value
1-2 Symbol ##
3 Unused
4-7 GPS Week 1708
8 Unused
9-23 Seconds of Week 0.00000000
24 Unused
25-38 Epoch Interval 300.0000000
39 Unused
40-44 Modified Julian Day Start 56201
45 Unused
46-60 Fractional Day 0.00000000

Line 3: ('+',i5,3x,17i3)
Column Description Allowed or Sample value
1-2 Symbol +
3-4 Unused
5-6 Number of Satellites 31
7-9 Unused
10-12 Satellite ID for the 1st satellite 1
nd
13-15 Satellite ID for the 2 satellite 2
* * *
* * *
* * *
th
58-60 Satellite ID for the 17 satellite 18
Date last modified: February 20, 2020 Approved for public release, 17-808.
Lines 4 to 7: ('+',8x,17i3)
Column Description Allowed or Sample value
1-2 Symbol +
3-9 Unused
10-12 Satellite ID for the next satellite 19
* * *
* * *
* * *
58-60 Satellite ID for the last satellite 0

Line 8 to 12: ('++',7x,17i3)

Column Description Allowed or Sample value
1-2 Symbol ++
3-9 Unused
10-12 Satellite Accuracy for the 1st satellite 0
13-15 Satellite ID for the next satellite 0
* * *
* * *
* * *
58-60 Satellite ID for the last satellite 0

Lines 13 to 14: ('%c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc')
Column Description Allowed or Sample value
1-2 Symbol %c
3 Unused
4-5 Characters cc
6 Unused
7-8 Characters cc
9 Unused
10-12 Characters ccc
13 Unused
14-16 Characters ccc
17 Unused
18-21 Characters cccc
22 Unused
23-26 Characters cccc
27 Unused
28-31 Characters cccc
32 Unused

Date last modified: February 20, 2020 Approved for public release, 17-808.
Column Description Allowed or Sample value
33-36 Characters cccc
37 Unused
38-42 Characters ccccc
43 Unused
44-48 Characters ccccc
49 Unused
50-54 Characters ccccc
55 Unused
56-60 Characters ccccc

Lines 15 and 16: ('%f 0.0000000 0.000000000 0.00000000000 0.000000000000000')

Column Description Allowed or Sample value
1-2 Symbol %f
3 Unused
4-13 Common Float 0.0000000
14 Unused
15-26 Common Float 0.000000000
27 Unused
28-41 Common Float 0.00000000000
42 Unused
43-60 Common Float 0.000000000000000

Lines 17 and 18: ('%i 0 0 0 0 0 0 0 0 0')

Column Description Allowed or Sample value
1-2 Symbol %i
3 Unused
4-7 Integer 0
8 Unused
9-12 Integer 0
13 Unused
14-17 Integer 0
18 Unused
19-22 Integer 0
23 Unused
24-29 Integer 0
30 Unused
31-36 Integer 0
37 Unused
Date last modified: February 20, 2020 Approved for public release, 17-808.
Column Description Allowed or Sample value
37 Unused
38-43 Integer 0
44 Unused
45-50 Integer 0
51 Unused
52-60 Integer 0

Lines 19 to 22: ('/* CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC')

Line 23 (The Epoch Header Record): ('*',i6,4i3,f12.8)

Column Description Allowed or Sample value
1-2 Symbol *
3 Unused
4-7 Year Start 2012
8 Unused
9-10 Month Start 10
11 Unused
12-13 Day of Month Start 1
14 Unused
15-16 Hour Start 0
17 Unused
18-19 Integer 0
20 Unused
21-31 Integer 0
32-60 Unused
Epoch Headers in Line 23 repeat for each new epoch with vehicle position and velocity records following.

Line 24 (The Position and Clock Record): ('P',i3,4f14.6)

Column Description Allowed or Sample value
1 Position P
2-4 Vehicle ID 1
5-18 x coordinate (km) -1577.901589
19-32 y coordinate (km) 16285.584053
33-46 z coordinate (km) -20920.350325
47-60 Clock time (µs) 275.849218
Line 24 will include an 'E' in column 75 to designate an Event in the Position and Clock Record.
('P',i3,4f14.6,14x,'E')

Date last modified: February 20, 2020 Approved for public release, 17-808.
Line 25 (The Velocity Record): ('V',i3,4f14.6)
Column Description Allowed or Sample value
1 Velocity V
2-4 Vehicle ID 1
5-18 x coordinate (dm/s) -25096.728698
19-32 y coordinate (km) 8665.572021
33-46 z coordinate (km) 8818.525202
47-60 Clock correction rate of change (µs/s) 0.015870

***Lines Twenty-four and Twenty-five repeat for each vehicle in the epoch. ***

Date last modified: February 20, 2020 Approved for public release, 17-808.