From: gurtner@ubeclu.unibe.ch (WERNER GURTNER) Author: W. Gurtner Date: 06 May 1999 12:46:20 Subject: [IGEXMail-0328] Z18 Tracking Problems? Sender: owner-igexmail@ensg.ign.fr Precedence: bulk ****************************************************************************** IGEX Electronic Mail 06-May-1999 12:46:20 Message No 0328 ****************************************************************************** Author: gurtner@ubeclu.unibe.ch (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