Subject: [IGEXMail-0328] Z18 Tracking Problems?
From: [email-masked] (WERNER GURTNER) Author: W. Gurtner
Date: 06 May 1999 12:46:20

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IGEX Electronic Mail    06-May-1999 12:46:20                   Message No 0328
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Author: [email-masked] (WERNER GURTNER)
Subject: Z18 Tracking Problems?

 Author: W. Gurtner

 IGEX-98: Tracking problems of Z18 receivers?
 ********************************************

 On February 22, 1999 (as an example) we collected data from 15 Z-18 receivers
 of the IGEX-98 network.

 Today we found data of May 2, 1998 from seven Z-18 receivers only!
 The data of those seven receivers show distinct gaps, there seems to be
 some correlation between the various stations.

 See below a statistics of the number of satellites tracked per station for
 these two days with a bin width of 20 minutes.

 It may be that the tracking problems are related with the GPS satellite 27
 tests that have been performed by the DOD, although the problems still have
 not disappeared completely after last Sunday.

 The question also is if the small number of Z-18 stations submitting data
 is linked to this instrument problem or if it is due to other reasons, like
 the decision not to continue after the formal end of the IGEX-98 campaign
 (although we are not aware of such decisions with the exception of one or
 two stations).

 May we ask the Z-18 station operators to check if the receivers are still
 collecting data, or to inform us through an IGEXMail or directly if there are
 changes in the status of the stations.

 We send this information also to Magellan/Ashtech for comments about the
 apparent tracking problems.

 Any informations about these topics are highly appreciated.

 Daniel Ineichen, Werner Gurtner
 Astronomical Institute
 University of Berne

 DOY 053, FEBRUARY 22, 1999: 15 ASHTECH Z-18 SITES PROVIDING DATA
 ---------------------------

 GPS SATELLITES :

 GRAB |767688**98897787788678677687778899**998788866786668887776777888997778777
 IRKZ | 88766776557787666777766546677777878777878776578787665668887767***88996
 KHAB | 8978741667775755857767876686966777769*88767787788788676678888999899779
 KR0G |767876899887767999965777689876687998997766787557678777776658898786788867
 LRBA |75777898888678767778985787888*986888988986667665667777966786488888766777
 MDVZ |6867788975887778   87766757778789786667867877656787777657977898688896976
 METZ |                         99996589*9998766788876
 MTKA |88878877656775577777777876667777776799998788978887789877887789*99*99*989
 OS0G |755668997866677687776666788886686999886557676665657777765687787775676766
 STRR |655688874565556666556444556656677666755776446545666677765555554555555456
 THU2 |                                            7888998888*87889867999*9*888
 TSKA |88767764466776656775778857767667776799777888888877688767777788999999*889
 WTZZ | 76778*998887786788877578788888879****86877  786568788776678788777667877
 YARR |888886788878797667786798988**9998678767778878678989*78899867687678886678
 ZIMZ |666778*988877787677788678878798768*9988887666766576776766787878777876777
 -----+-----------------+-----------------+-----------------+-----------------+
      0                                  12                                  24
                                                   *: More than 9

 GLONASS SATELLITES :

 GRAB |676754443455544444444333333334444655564465676654443355543334566676457654
 IRKZ | 6564434432334443334344455434334444344445444455544444223444333446677754
 KHAB | 6566551554443445645444555444456544445566556465444233343423343566776125
 KR0G |555675555544455644443443344335455556654554765544453555544334555665555456
 LRBA |666665543445533444444433433345455555553566666644544455543434555667556555
 MDVZ |7777656445445565   43343354434555665565554665654434445643334566677667676
 METZ |                         4433455666656565577564
 MTKA |544544533344445656555555544444433333445556664344333333333324456666677666
 OS0G |677774552455545444444334334336556666565564765545345456543335556666655666
 THU2 |                                            3444566434434444425455666555
 TSKA |544444433344433656545555544444433333444556664343333333332334445666676666
 WTZZ | 766645434555344444443334334344446555544656  655444465543335556777556555
 YARR |333335555666664755555453334445544344444433223333333344556667554644333333
 ZIMZ |776654542355544444444433433244434555554565566554544345543434556665456554
 -----+-----------------+-----------------+-----------------+-----------------+
      0                                  12                                  24

 DOY 122, MAY 2, 1999:  7 ASHTECH Z-18 SITES PROVIDING DATA
 ---------------------

 GPS SATELLITES :

 GRAB |
 IRKZ |
 KHAB |
 KR0G |388975466768987668798888775678844767668666566778            677789976565
 LRBA |
 MDVZ |                79996786686688865687776676676788858988795797777889778767
 METZ |48888557658889956              667877887668679             87669*9986477
 MTKA |57777768888667787776769999877897888788987788779                    66776
 OS0G |357666556668897667             6555677776657777            5577888786668
 STRR |
 THU2 |5787588888*88989**898 9889996778878877779767888679           98977888878
 TSKA |
 WTZZ |
 YARR |4777787788888**99876887677788787889897            788866778898
 ZIMZ |
 -----+-----------------+-----------------+-----------------+-----------------+
      0                                  12                                  24

 GLONASS SATELLITES :

 GRAB |
 IRKZ |
 KHAB |
 KR0G |663355454444466543433444444223343445545545544544            445554565434
 LRBA |
 MDVZ |                45334444553544345545443534445444444344455555557776765456
 METZ |65455545544466644              334365455464455             4345556555445
 MTKA |54445645454333333333444466566565655453443444445                    44454
 OS0G |6656664455446555442            4554564433544444333 355454446655677665456
 STRR |
 THU2 |344443244344444544344 343234444553444345544555344455443       2255654455
 TSKA |
 WTZZ |
 YARR |34313244334355666664577567452233333334            443233333335
 ZIMZ |
 -----+-----------------+-----------------+-----------------+-----------------+
      0                                  12                                  24