APSG-4    
                          (Asian Pacific Space Geodesy-4)
                       
                              1998 November 12

                             Notes prepared by
                     Dr. Qian Zhihan, Shanghai Observatory
                          Cynthia Thomas, NVI/GSFC


Schedule name:  APSG4.SKD on CDDISA

Nominal Start:  23:00 U.T. on November 12 (day 316) 
                first observation at 23:00 U.T. on 1308-326 for GC-HO-KK-TS
                first observation at 23:00 U.T. on 4C39.25 for SH-UR

Duration:  24 hours

Nominal Stop:   23:00 U.T. on November 13 (day 317)
                last observation at 22:53 U.T. on 0727-115 for HO-UR
                last observation at 22:54 U.T. on 0749+540 for SH   
                last observation at 22:56 U.T. on 0718+793 for GC-KK-TS        
                             
Correlator: Washington  

**Frequency Sequence**: CDPSX - Standard CDP SX sequence.
                        (360 MHz wide at X, 85 MHz wide at S)         
     

          1 letter  2 letter
Station     Code     Code    # of tapes    # of obs     Occupation Code
Fairbanks    A        GC      1 (TT)        368           40476601
Hobart       H        HO      3 (HDT)       248           72425901
Kokee        K        KK      1 (TT)        392           72983001   
Seshan       D        SH      3 (HDT)       292           72336101
Tsukuba      T        TS      1 (TT)        389           73452301
Urumqi       U        UR      3 (HDT)       295           73303201  


Purpose
=======
This is second of the second group of two Asian Pacific Space Geodesy (APSG)
experiments. The primary purpose of these APSG sessions is to continue
monitoring the relative motions of the plates in the Asia-Pacific region. 
These sessions involve sites on the four plates. Tsukuba and Fairbanks are on 
the North American Plate, Hobart is on the Australian Plate, Seshan and Urumqi 
are on the Eurasian Plate, and Kokee is on the Pacific Plate. Thus, these 
sessions will produce critical data for the investigation of the current 
crustal motions in the Asia-Pacific region combined with the data from the 
APSG SLR and GPS campaigns which will also be performed in November 1998.
Also, these experiments will improve the accuracy of the geocentric 
coordinates of the participating stations, especially Urumqi and Tuskuba.

Station Information
===================
Tsukuba, the new Japanese station operated by GSI, will replace Kashima
in this network. Kashima participated in the first two APSG experiments
but Tsukuba is more sensitive and will make the APSG network more robust.

Schedule
========
This is a new schedule generated by C. Thomas with the automatic mode of
sked. The following are the characteristics of the schedule:

1) This schedule was optimized for sky coverage.

2) Only the observations in the previous two hours of the schedule were 
considered for the minor options. The best 50% of the configurations
were considered for minor options.

3) The "minor options" were set to select observations to maximize the 
total number of observations, to minimize the idle time between scans,
and to minimize time between scans on the same source by thirty minutes.

5) The minimum  SNR limits for most baselines were set to 20 for X-band
and 15 for S-band.   

6) This schedule was made using 64 sources which helped improve the sky
coverage. 

Flux Information
================
Several years ago John Gipson wrote a program called snranal which 
compares the measured performance of an experiment with respect to the 
predicted.  One of the things this program calculates is an empirical 
flux density for each source. Recently J. Gipson compared the fluxes 
generated by this program with those from more careful modeling.  The 
agreement is generally good (~15%) for those sources which have been 
observed more than 20 times. In order to account for changes in the flux 
catalog since the last update, J. Gipson adjusted the fluxes in the flux 
catalog for the sources in the current source catalog using the 98AUG11
CORE-A042, 98AUG17 EURO44, and 98AUG25 experiments.

Procedures
==========
Please generate the procedures for this session using drudg.

Correlation
===========
This experiment will be correlated at the Washington Correlator with all
baselines being correlated.


   SKED Summary from file ./apsg4.skd for experiment APSG4   

      (all scans with at least one subnet station)

  SOURCE |0           6           12          18          | #SCANS #OBS #Obs/bl
 0003-066I      xx x x   xx  x xx         xx              I    11    19   3.5
 0048-097I         x x x x xx  x  xx  x x x               I    12    51   8.4
 0059+581Ix x x xxx xx x   xx x  xx  x  x x x  x  xx x xx I    24   112  11.9
 0104-408I        x xx x xx x xx x xxx xx x               I    16    24   4.4
 0119+115I     x x x x xx  x x  x  x  x    xx             I    13    74  10.2
 0119+041I      xx x xx   x             x x x x           I    10    16   2.3
 0208-512I              xx  x x  x  xx  x                 I     8     8   1.1
 0229+131I       x x x    x               x x  x   x      I     8    13   1.8
 0235+164I                 x                              I     1     1    .1
 CTA26   I           xx  x x x xxx x  x x       x  x      I    13    23   3.6
 0402-362I              x   x x x xxx xx  x x x  x x      I    14    30   5.9
 0454-234I                  x x  xx xx xx x x x  xx xxx   I    16    45   9.3
 0458-020I               x   x  x  x     x   x x x xx  x  I    11    15   2.4
 0528+134Ix            xxx  xx x xxxx  x x x x x x xxx xx I    22   110  15.0
 0537-441I                             x  x x x x         I     5     7   1.1
 0552+398Ix x x  x x  x xx  xx xxx xx  xx   xxx  x xx x xxI    26    98  12.0
 0556+238I               x   x xx             x   x x  xx I     9    16   1.9
 0718+793I  x   x   x  x x  x x  x   x   x    x    x   xx I    14    28   2.5
 0727-115Ixx                         xx xx x x x xx x xxx I    15    67  13.2
 0749+540I x x x x  x x xx xx x x x x    x   x  x x x  x xI    21    86   9.4
 0804+499I     x   x     x  x xx x   x x    x x       x   I    12    39   4.5
 0805+410I                     x x x     x                I     4    13   1.5
 0823+033Ix xx x                    x x x xx     x    x  xI    12    26   3.6
 OJ287   Ix    x                     x                x   I     4     4    .5
 0919-260I x                               x      x   x   I     4     6   1.6
 0920-397Ix                                    x    x x   I     4     4   1.4
 4C39.25 Ix x xx x  x x x    x x   x xx x     x xx x xx x I    21    79  14.6
 OK290   I  xx  x              x x  x x x x x   x x x x  xI    15    33   3.4
 0955+476I x  xx x  x  xx  x  xx   x  x       x         x I    14    40   4.4
 1034-293Ix x                           x  xx  xx   x x  xI    10    26   5.3
 1044+719I  x x x   x   x   x x  x x x   x  x    x   x x xI    16    89   8.3
 1053+815I       x        x         x x    x              I     5     5    .5
 1104-445I                                          x x x I     3     3   1.0
 1124-186Ix xx  x                           x xx x  x x   I    10    29   5.9
 1128+385I  x           x           x     x  x x  x       I     7    21   1.8
 1144-379I x xx x                            x  x x xx  xxI    11    24   4.8
 1219+044Ixx       x                 x  x x x  xx    x    I    10    16   2.2
 1255-316I  x  x                                    x x   I     4     4    .7
 1300+580I  x x  xx  x x    x     x  x    x x   x  x      I    13    23   2.3
 1308+326I x   x  x x   x            x    x xx   x x x xxxI    15    51   6.9
 1313-333I           x                       x    xx xx  xI     7     7   1.2
 1334-127Ix           x                           x xx xx I     7     9   4.2
 1351-018I            x                   x      x  x x  xI     6     8   1.3
 1357+769I    x    x   xx   x  x   x         x x   x   x xI    12    67   6.1
 1424-418I x x   x x                         x    xx xx x I    10    14   2.6
 1451-375I  x   x  x  x                                 x I     5     9   1.9
 1606+106Ix       x xx   x xx                 x    xxx xx I    13    34   4.6
 1622-253Ix  x x      x  xx                               I     6     8   1.9
 NRAO512 I x xx x x x x x x x xxx xxx  x    x x    xxx x xI    24    87  10.8
 1726+455I   x x     x      x x x      x   x       x x    I    10    16   1.7
 1739+522Ix x x  xx xx  x x x x x x  x x  x   x  x x x xx I    22    90  10.1
 1741-038Ixx x xx xx xx  xxx xx                     x   x I    16    93  14.9
 1749+096I x  x xx       x  x xx x                 xx   x I    12    37   5.0
 1908-201I    x    xx  x xx       x                       I     7    11   2.7
 1921-293I xx xxx xx x x x x x x                       x xI    15    27   5.3
 1954-388I x x x xx x xxx x xx x x                      xxI    16    25   4.8
 1958-179Ix  xxx x x  x  x   x x x                        I    11    27   5.6
 2005-489I             x                                  I     1     1    .1
 2052-474I              xx                                I     2     2    .3
 2121+053Ixx x x x x   x  x  x    x x x                 x I    13    55   7.8
 2128-123I         xx  xx x  x   x    x                   I     8    12   3.4
 2145+067I   x  xx x xx   x  x   x  xx                    I    11    43   6.0
 2234+282Ixx x x xxx x       x      x xx  x  x   x        I    15    19   1.9
 2255-282I            x x x    x x x x                    I     7     7   2.0
 Total scans, obs:                                            719  2086

 Average number of obs. per baseline per source (normalized by up-time) =   4.9
 Min =    .0   Max =   38.6 (Baseline Gc-Kk on 1334-127)   RMS =   5.8

 Total time:       1438 minutes ( 24.0 hours).

 Key:     Gc=GILCREEK   Ho=HOBART26   Kk=KOKEE      Sh=SESHAN25   Ts=TSUKUB32
          Ur=URUMQI  

                  Gc  Ho  Kk  Sh  Ts  Ur  Avg
 % obs. time:     45  36  45  40  37  41  41 
 % cal. time:      4   2   4   3   4   3   3 
 % slew time:     21  30  18  41  12  27  25 
 % idle time:     28  30  31  14  45  27  29 
 # of tapes :     .8 2.2  .8 2.5  .7 2.5
 total # scans:  368 248 392 292 389 295 330 
 # scans/hour :   15  10  16  12  16  12 13.8
 Avg scan (sec): 105 125  99 120  83 121 108 

      # OF OBSERVATIONS BY BASELINE

   | Gc  Ho  Kk  Sh  Ts  Ur   StnTotal 
 --------------------------------------
 Gc|368  36 261 111 190 143      777 
 Ho|    248 130 113 134  65      492 
 Kk|        392  84 177  68      752 
 Sh|            292 185 209      756 
 Ts|                389 180      576 
 Ur|                    295      819 


 Number of  2-station scans:  381
 Number of  3-station scans:  185
 Number of  4-station scans:  110
 Number of  5-station scans:   31
 Number of  6-station scans:   12

 Total # of scans, observations:   719    2086


 Average baseline components for all observations
  Average XY     = 4255.
  Average XZ     = 4285.
  Average YZ     = 4931.
  Average length = 5812.