ERP格式说明 GPS IGS
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IGS Electronic Mail Fri Jul 10 6:28:41 PDT 1998 Message Number 1943
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Author: AC Coordinator
Subject: New IGS ERP Format (version 2)
Dear Colleagues,
To accommodate an increased resolution in the current IGS erp format,
primarily for the sake of meaningful (unscaled) formal solution sigmas
(which in some cases were reduced down to 1 or 2 of the .01 mas units of
the current IGS erp format), an enhanced resolution format was agreed upon
by all ACs after discussions amongst ACs and both services of the IERS (the
Central Bureau and the Rapid Service). The new format (version 2, see the
example below) is almost identical to the current IGS erp format, the only
difference being the increased resolutions for the Polar Motion
coordinates, their rates (.001 mas) and UT/LOD (.0001 ms) and their
respective sigmas. The new IGS erp format must be identified by the string
"version 2", l.c., on the first line, starting in Col.1. Please note that this
increased resolution does not imply any precision of GPS solutions, which
in fact even for the current best GPS solutions is much worse.
The new format will be implemented for all IGS combined products (i.e. the
IGS, IGR and IGP erp files) starting on Week 0966/Day 0 (MJD 51006/ July
12/98). All ACs are expected to change to the new erp format in the near
future as well.
With many greetings
Jan Kouba & Yves Mireault
------------proposed format version 2----------------------
field contents/HEADER comment
========================================================================
1 MJD modified Julian day, with 0.01-day precision
2 Xpole 10**-6 arcsec, 0.000001-arcsec precision
3 Ypole 10**-6 arcsec, 0.000001-arcsec precision
4 UT1-UTC, UT1R-UTC
UT1-TAI, UT1R-TAI 10**-7 s, 0.0000001-s precision (.1 us)
5 LOD, LODR 10**-7 s/day 0.0001-ms/day precision (.1 us/day)
6 Xsig 10**-6 arcsec, 0.000001-arcsec precision
7 Ysig 10**-6 arcsec, 0.000001-arcsec precision
8 UTsig 10**-7 s, 0.0000001-sec precision (.1 us)
9 LODsig 10**-7 s/day, 0.0001-ms/day " (.1 us/day)
10 Nr number of receivers in the solution (integer)
11 Nf number of receivers with "fixed" coordinates
12 Nt number of satellites (transmitters) in the solution
(integer)
optional (field 11- , only some may be coded, the order is also optional):
13 Xrt 10**-6 arcsec/day 0.001-mas/day precision
14 Yrt 10**-6 arcsec/day 0.001-mas/day precision
15 Xr
tsig 10**-6 arcsec/day 0.001-mas/day "
16 Yrtsig 10**-6 arcsec/day 0.001-mas/day "
17 XYCorr X-Y Correlation 0.001 precision
18 XUTCor X-UT1 Correlation 0.01 "
19 YUTCor Y-UT1 Correlation 0.01 "
EXAMPLE : version 2 --------------
version 2 (on the first line, starting col. 1, l.c.)
MJD Xpole Ypole UT1-UTC LOD Xsig Ysig UTsig LODsig Nr Nf Nt Xrt Yrt
10**-6" 10**-6" 0.1 us .1 us/d 10**-6" .1 us .1 us/d 10**-6/d
49466.50 183150 349880 -0802200 29120 180 210 500 600 20 12 25 500 -2240
49467.50 183411 347871 -0832600 27460 180 200 600 600 21 12 25 471 -2251
49468.50 182742 345652 -0861800 25490 180 210 600 600 20 12 25 442 -2252
---End of example of version 2------------