[IGSMAIL-111] EMR analysis results for the GPS week # 663 (Sep 20-26,1992)
Carey
Carey
Fri Oct 2 17:44:11 PDT 1992
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IGS Electronic Mail 2-OCT-1992 17:44:11 Message Number 111
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from: J. Kouba
Subject: EMR analysis results for the GPS week # 663 (Sep 20-26,1992)
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submitted by:
J. Kouba * , P. Tetreault, R. Ferland, F. Lahaye, M. Caissy, P. Heroux
Geodetic Survey Division (GSD), Surveys Mapping & Remote Sensing Sector
(SMRS), Energy Mines and Resources (EMR), 615 Booth Str., Ottawa, K1A 0E3
* on secondment to the Geodetic Survey from the Geophysics Div., Geological
Survey of Canada (GSC), EMR, 1 Observatory cresc., Ottawa, K1A 0Y3
Our analysis utilizes the JPL GIPSY/OASIS II (UNIX) software system
and data from all (up to 7) Canadian stations augmented by up to 10, globally
distributed, core stations (see Table 1 for the list of stations).
Submitted results start with GPS Week # 663 and include only days when
AS was not invoked. This effort is a part of a joint pilot project to test the
so called "Active Control System" in Canada and involves the Geodetic
Survey (GSD), SMRSS, the Geophysics Division and Pacific Geoscience Centre of
the Geological Survey of Canada, all three institutions are part of the
Department of Energy, Mines & Resources (EMR).
Table 1 : Station Summary (also indicated are day no. for which a
particular station is not included in the daily solution, either due to being
down or data being late)
station IGS code missing day no. of 1992
Albert Head, CAN ALBH
Algonquin, CAN ALGO
Fairbanks FAIR 269 (most of this day)
Goldstone GOLD
Hartebeesthoek HART
Kokee Park KOKB 264 -> 270
Madrid MADR
Penticton, CAN DRAO
Prince Albert, CAN PRAL
Santiago SANT 269
St. Johns, CAN STJO
Canbera CANB
Tromsoe TROM
Wettzell WETT 268 (this day contains data from 267!)
Yarragadee YAR1
Yellowknife, CAN YELL
SOLUTION CHARACTERISTICS
Reference frame and orientation
Nominally ITRF91 at epoch 1992.5, realized by constraining the
following stations at the IGS coordinates (see IGS message #90):
Table 2: Constrained stations
Station code L1p.c. X(m) Y(m) Z(m) apriori sigmas
Algonquin ALGO .192m 918129.616 -4346071.224 4561977.800 .002 .002 .002
Fairbanks FAIR .194 -2281621.327 -1453595.775 5756961.976 .02 .02 .02
Tromsoe TROM 2.551 2102940.451 721569.379 5958192.072 .02 .02 .02
Wettzell WETT .078 4075578.683 931852.634 4801569.980 .02 .02 .02
Yarragadee YAR1 .151 -2389025.331 5043316.830-3078530.926 .02 .02 .02
The remaining stations are considered unknown (with 50 m apriori sigmas).
Orientation is realized through the above coordinates and the fixed DUT1
values from IERS (Bull. B).
Constants and models
- no change, see the IGS mess. #101 for details -
Estimation strategies
- no change, see the IGS mess. #101 for details -
ALGO was used as time reference.
Table 3: Summary of estimated parameters and apriori weighting
(L3 and P3 undifferenced phase and smoothed pseudorange sigmas of 0.005m and
.5m were used, > 15 degrees @ 5 min.)
parameter model apriori weighting (sigmas)
station X,Y,Z unknown parameters 50m (fixed stations .002-.02m)
pole x,y " " 3m; (DUT1 fixed)
trop. zen. delay " " 0.2m
trop. bias random walk .01m/sqrt(1hour)
satellite states unknown parameters 1km; .005m/s
rad. press Gx,Gz " " 25%
rad. press Gy " " 2.0 10e-9 m/s^2
initial real cy amb. " " 300000km
station clocks white noise 1s
satellite clocks " " 1ms and .1ms for Block I and II,resp.
Aposterioi variance factors typically are between 0.5 and 1.0. Due to
problems with data quality for the AS days the results for the corresponding
days (with AS turned on) are not included here.
SUMMARY OF CANADIAN EMR SOLUTION
1. Analysis centre : Geodetic Survey Division (GSD), SMRSS , EMR
2. Solution identifier: Submission 920930
3. Software used : GIPSY/OASIS II (UNIX )
4. Definition of Terrestrial frame:
origin : Nominally ITRF91
orientation : " "
reference epoch : 1992.5
velocity of light : 299792458 m/s
GM : 389600.4414 km^3/s^5
gravity model : GEMT3( 8,8) +C21+S21
permanent tide corr: None
ocean loading : Pagiatakis, global model
5. Adjusted parameters:
undifferenced phase and smoothed pseudorange data > 15 degrees @ 5 min.
single day (24h) arc with 6 IC and 3 rad. parameters per satellite (18
satellites)
tropospheric zenith delay corr. parameter augmented with random walk stoch.
process
initial phase ambiguity parameters (one for each satellite station pass or
initial phase)
station positions X,Y,Z, up to 17 stations, ALGO constrained at 2mm, FAIR,
TROM, WETT and YAR1 at 2cm sigmas.
x and y pole position once a day (DUT1 fixed; x,y apriori sigma=3m)
station clock biases once per each epoch/station (except for ALGO h. maser
which provides the time reference) with sigma 1 s
satellite clock biases once per each epoch/satellite with 1ms or .1ms sigma
Pole solution for non AS days
MJD date x(") y(") DUT1(s) xsig ysig utsig xyc
48885.5 9/20/92 AS on
48886.5 9/21/92 AS on
48887.5 9/22/92 .03491 .50738 .30568 .00060 .00044 0 0
48888.5 9/23/92 .03791 .50796 .30365 .00050 .00031 0 0
48889.5 9/24/92 .03969 .50874 .30162 .00059 .00034 0 0
48890.5 9/25/92 .04159 .50778 .29954 .00062 .00044 0 0
48891.5 9/26/92 AS on
Products generated:
The following products are generated and uploaded into CDDIS @ NASA/GSFC
EMR06637.EPH precise GPS ephemeris for week # 663 in sp3 NGS format
EMR06637.ERP pole x y solutions for week# 663
EMR06637.SUM name of this text file
remarks on EMR's products:
1. only days with no AS included
2. ALGO hydrogen maser used as a time reference. In the sp3 EPH file sat.
epochs with no reference (e.g. ALGO not observing a satellite) have a value
of 99999. microseconds.
ALGO clock error was about -0.35 microsec during this period.
3. ephemeris refers to the mass centre of SV
--
Mark Caissy
Geodetic Survey of Canada
mark at sun470.geod.emr.ca
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