Subject: [IGSREPORT-99] JPL analysis report (week 678)
From: David C Jefferson
Date: 21 JAN 1993 13:51:05

***********************************************************************
IGS Electronic Report     21-JAN-1993 13:51:05       Message Number 99
***********************************************************************

From:     David C Jefferson
Subject:  JPL analysis report (week 678)
----------------------------------------

Submitted by

J F Zumberge, G Blewitt, M B Heflin, D C Jefferson, F H Webb

all at the Jet Propulsion Laboratory, California Institute of Technology, 
Pasadena, CA  91109.

The following files have been posted on BODHI (for access to BODHI contact
[email-masked]):

______________________________________________________________________________
filename               contents
______________________________________________________________________________
jpl06787.sum           This text file.
jpl06787.erp           Earth rotation parameters for GPS week 678.
jpl06787.sp1           GPS ephemerides for GPS week 678, sp1 format.
jpl06787.sp3            "       "       "   "   "    " , sp3   "   .
______________________________________________________________________________

For this week's analysis, we continue to deweight data from PRN11/GPS08, as
its repeatablilty results remain at the few-meter level. Additionally, we
begin to include results for the recently launched PRN29/GPS29. Because our
analysis indicates several-meter-level daily repeatabilities for this new
satellite, we will deweight its data for a while. It should be noted as well
that solar radiation pressure was estimated as a constant (instead of 
stochastically) for this satellite. Future analyses will utilize stochastic
estimation.  Finally, PRN12/GPS10 exhibits unmodelled behavior on January 5 
(day 005); deweighting its data did not improve its orbit comparison results.

A preliminary review of our results revealed that there was an approximate
1.2-ms drift in the receiver clock at FAIR (Fairbanks, Alaska) on January 6
(day 006). The clock continued to be anomalous on the next day as well. 
Because of this, and also due to a significant absence of tracking data from 
FAIR on January 8 and 9, we have changed our reference clock to ALGO (Algonquin 
Park, Ontario, Canada) as of January 6, 1993.

Beginning this week, JPL has modified its "GROUND STATION INCLUSION TABLE".
Actually, this new version is simply a more informative variation of the
original. A particular station's presence on any given day is now indicated by
a number, instead of just an 'X'. This number is a percentage, and reflects how
much data from a station was used for the corresponding date of analysis. These
percentages are based on a "normal" number (M) of total GPS measurements
(pseudorange and carrier phase) from all of the regularly used ground sites,
and exclude those measurements rejected as outliers by our software. After
monitoring about 6 weeks of daily analysis results, it was determined that:

                             M =~ 3400 measurements

[Because we use a 5-minute data interval, of which there are 360 in each
30-hr period, the 3400 means that stations, on the average, typically
see 3400/(360*2) =~ 5 satellites at any given time.  The factor of two
accounts for the two data types.]

For example:
   The column for January 5 indicates that, for JPLM, 0.96 * 3400 =~ 3264
   measurements were used over the 30-hour processing interval. In general,
   the number is:

                  % Data Used = (n/M)*100 = (n/3400)*100,

   where n is the number of measurements for an individual site.

As with the previous Site Inclusion Table, a blank entry indicates that there
were no data used over the entire 30-hr period of analysis for that station/day,
and asterisks mark constrained stations.
-----------------

WARNING: PRN's 11 and 29 (GPS08 and GPS29) show unmodeled behavior at the meter-         level for week 678 and have been deweighted.
WARNING: FAIR exhibits anomalous clock behavior starting 1/6/93; consequently,           JPL has changed its reference clock from FAIR to ALGO as of this date. 

JPL LODR TABLE                               GPS week 678 (1993 Jan 03 - Jan 09)
  MJD       LODR     +/-
          (ms/day)
 48990.5    2.44     0.05
 48991.5    2.56     0.05
 48992.5    2.39     0.06
 48993.5    2.68     0.05
 48994.5    2.56     0.05
 48995.5    2.23     0.05
 48996.5    2.27     0.05
END LODR TABLE

NOTE: In the following table, UT1R-UTC are the assumed nominal values from
IERS Bulletin-B predicts; estimated LODR values are given in the previous
table. See IGS Mail Message 97 for details.

JPL UTPM TABLE                               GPS week 678 (1993 Jan 03 - Jan 09)
  MJD       X        Y       UT1R-UTC XSIG    YSIG   UTSIG  RMS  XYC  XUC  YUC STA SAT PASS    
           ''        ''        sec     ''     ''      sec
 48990.5   .20990   .35151   .06232  .00017  .00015  .00000  .0 -.08  .00  .00  25 21  0
 48991.5   .20998   .34859   .06004  .00016  .00015  .00000  .0 -.06  .00  .00  25 21  0
 48992.5   .21030   .34658   .05777  .00017  .00016  .00000  .0 -.01  .00  .00  26 21  0
 48993.5   .21071   .34394   .05549  .00013  .00014  .00000  .0  .01  .00  .00  28 21  0
 48994.5   .21100   .34115   .05321  .00015  .00017  .00000  .0  .08  .00  .00  28 21  0
 48995.5   .21144   .33808   .05092  .00014  .00016  .00000  .0  .09  .00  .00  27 21  0
 48996.5   .21269   .33568   .04864  .00013  .00015  .00000  .0  .09  .00  .00  26 21  0
END UTPM TABLE

The following table indicates the "3-dimensional orbit repeatability", as 
defined in IGS Mail Message 37, for GPS week 678:
["3d rss" = sqrt(xrms**2 + yrms**2 + zrms**2)]

JPL ORBIT REPEATABILITY TABLE                GPS week 678 (1993 Jan 03 - Jan 09)
      93  1  3   93  1  4   93  1  5   93  1  6   93  1  7   93  1  8   93  1  9
prn   3d rss (m)
  2       0.66       0.46       0.65       0.67       0.47       0.33       1.14
  3       0.34       0.29       0.33       0.42       0.46       0.49       0.73
 11       2.04       1.97       1.58       2.69       1.34       1.76       1.84
 12       0.69       1.08      11.56       4.42       0.79       0.52       0.47
 13       0.36       0.38       0.57       0.70       0.47       0.61       0.48
 14       0.44       0.23       0.59       0.85       0.47       0.54       0.59
 15       0.44       0.42       0.36       0.82       0.35       0.22       0.43
 16       0.12       0.25       0.22       0.55       0.33       0.45       2.65
 17       0.20       0.41       0.24       0.50       0.50       0.27       0.92
 18       0.19       0.24       0.29       0.43       0.19       0.43       0.39
 19       0.16       0.17       0.24       0.46       0.21       0.19       0.50
 20       0.30       0.43       0.30       0.66       0.41       0.39       0.48
 21       0.41       0.55       0.38       0.57       0.30       0.30       0.31
 23       0.63       0.83       0.81       0.79       0.55       0.75       0.68
 24       0.14       0.23       0.35       0.67       0.26       0.34       0.24
 25       0.29       0.48       0.29       0.35       0.36       0.40       0.20
 26       0.20       0.41       0.57       0.78       0.47       0.35       0.79
 27       0.25       0.24       0.27       0.55       0.28       0.24       1.36
 28       0.51       0.33       0.30       0.62       0.28       0.38       0.68
 29     178.78       3.03       2.32       2.55       3.34       3.77       8.17
 32       0.33       0.47       0.34       0.51       0.33       0.29       0.30
END ORBIT REPEATABILITY TABLE

As described in IGS Mail Message 37, the following table compares the JPL
precise ephemerides with those from the broadcast ephemeris:

JPL COMPARISON OF BROADCAST NAVIGATION MESSAGE WITH PRECISE EPHEMERIDES
      93  1  3   93  1  4   93  1  5   93  1  6   93  1  7   93  1  8   93  1  9
prn   3d rss (m)
  2       5.2        4.6        4.2        5.6        6.1        6.9        5.5 
  3      14.4       13.0       12.0       13.7       15.7       15.1       14.4 
 11       8.9       14.3       13.8        9.93      13.4        6.6        9.5 
 12       7.5       10.4        9.9       13.3       15.6       12.5       15.3 
 13       5.4        6.2        7.1        3.1        2.5        3.7        2.8 
 14      12.4        9.5        5.9        7.4        5.5        8.3        5.0 
 15       3.6        3.5        5.2        4.9        5.4        7.4        5.4 
 16       4.4        3.9        4.0        4.2        3.9        4.3        4.5 
 17       3.0        4.3        2.9        3.5        3.8        3.6        4.1 
 18       3.9        3.6        7.6        8.3        9.3        7.4        7.7 
 19       4.7        5.0        5.9        6.1        5.2        5.1        9.9 
 20       6.1        6.8        6.1        6.2        6.5        7.0        5.4 
 21       5.1        4.8        2.9        2.4        4.0        4.3        3.0 
 23       4.8        3.1        3.4        3.6        4.9        4.5        3.8 
 24       6.6        5.8        6.4        6.1        6.3        8.0        8.9 
 25       7.7        6.7        7.3        6.3        6.8        7.5        7.3 
 26       2.6        2.8        2.7        2.5        2.9        4.8        4.6 
 27      17.0       16.4       15.5       16.7       16.3       16.1       18.1 
 28       6.9        2.7        6.5        4.6       11.1        7.3        6.9 
 29      24.8       28.4       24.9       26.0       41.6       49.9       42.4 
 32      11.1       15.6       11.6        9.4        7.0        9.4        9.4 
END COMPARISON OF BROADCAST NAVIGATION MESSAGE WITH PRECISE EPHEMERIDES

The following table, as explained above, indicates which tracking sites were
used in this week's analysis:

JPL GROUND STATION INCLUSION TABLE           GPS week 678 (1993 Jan 03 - Jan 09)
      93  1  3   93  1  4   93  1  5   93  1  6   93  1  7   93  1  8   93  1  9
site    % data
ALBH      104        105        105        107        108        108        107
ALGO*      96         91         86         89         91         94        107
CANB      102         74         92        100        102        102        103
FAIR*     104        105         90         99         92          9
GOLD      104        104        102        102         88          9         69
HART*     111        111        108        108        111        111        111
JPLM       98         99         96         57         12        101        112
KOKB                             17        102        108        114        104
KOSG       46         65        108         64         41         20         99
KOUR                                       109        110        113        112
MADR*     100        101         98        100        102        100         99
MASP                                        94        109        111        111
MATE      107        103         90        102         92        100        108
MCMU      124        127        122        122         85        127        127
METS      110        109        106        110        111        111        113
ONSA       94         97         96         95        104        109         96
PAMA      101        103         99        101        103        102        101
PENT       61         30        103        103        103        100         96
RCM2       98        104        101        107        107        109        108
SANT*     109        110        108        111        113        113        113
STJO      103        104         99        103        104        101        102
TAIS      106        100         90          9         82        106        105
TROM*     107        120        118        123        123        125        125
USUD      108        109        109        106        109        110        108
WETB      101         98         96         98        103        105        108
YAR1*      93         91         89         84          6
YELL       59         81        100        113        111        116        114
_______________________
*Indicates fiducial site.
END GROUND STATION INCLUSION TABLE