All Ashtech uZ receivers in the western hemisphere at latitudes above about 50 degrees (at least those we could find) apparently stopped tracking or exhibited tracking problems shortly after 15:00 UT on 2003-09-26 (DOY 269). This condition lasted anywhere from 30 minutes to over 3 hrs at some stations. IGS station RESO (Resolute, lat N74-41-26, lon W94-53-35) stopped tracking completely and never recovered. It had to be completely reset. No other types of receivers were apparently affected.
If you have any explanation for this behaviour, please contact Mike Craymer (craymer@nrcan.gc.ca).
The following teqc plots illustrate the problem for those stations we operate. They are ordered from west to east. The plotting symbols are defined at http://www.unavco.ucar.edu/software/teqc/tutorial.html#sec_21.
Latitude 68-18-22 N
Longitude 133-31-37 W
IGS Site Log
Fairly evident as "C", "m" and "M" slips, and clock resets for nearly 1.5 hours, although SV's 11, 14 and 20 were tracked for about 20 min during this period.
Input RINEX file : invk2690.03o input RnxNAV file : invk2690.03n SV+------------------------------------------------------------------------+ SV 10|+ ^-Moooooooooo++ ++oooooooooo+m| 10 3|m_ _+ooooooooooooom+ _++ooooooooo| 3 15|o++^ _+Moooooooooooooom^ _+oooMo| 15 8|oooo+m+ __----oo;++ _++oooooooooo| 8 18|oooooo+m _ooooooooooooooo+m^ ++Io| 18 11|+ooooooooo++ _-oooooooooCoCC+m_ m| 11 21| _+IIo;ooooooooooo++ _++oooooo+^| 21 26|ooooooom+ _^+ooooooooo++_ _-ooooo| 26 27|o+m_ _+;Moooo1m^ _+oooooooooooooo| 27 28|oooooooooo+m _++oooooo+m_ _---ooo| 28 29|oooooom+ +moooooooooo+_ _^+ooooooo| 29 31|ooo+m _--mooooooooo+m+ _oooooooo| 31 23|++oooooom++ _--oooooooooooooo-_ _| 23 7|+oooooooooooooom_ ++oooo---M++_ _| 7 9|_-ooooooooooooo+m m+;ooooooo+m_ | 9 14| _+oooooooom++ ++oooooooooCoCCIm_ | 14 5| ++oooooooooooooo++ __--M----I+_ | 5 20| __+ooooooom+ ++oooCoCCooooooo+m | 20 4| _-oooooooooooom+ __--ooooooooo++ | 4 30| ++ooooooooooooo;+^ _+---Moooo++ | 30 24| _+ooooooooooooo+m_ _+oooooooooom+ | 24 25| _++ooooooo;IIm_ _m+o---mooooooII+_ | 25 6| ++oooooooo;;ooooom_ _++;2;2o;m+ | 6 17| ++;Ioooo;ooooooom+ _+;ooooooom+ | 17 1| _++oooooo+m _---ooooooooooooo+m | 1 13| _++ooooo;2+ ++ooooooooooooooo+_ | 13 16| __+oo;oooooooo++ _+;oooooooooo1+ | 16 2| ++IIoooooooo+m+ _-Mooooooooooo++_ | 2 -dn| 11 46 |-dn +dn| 1 1 1 1133 1 c566 11 |+dn +10|acaa988888888899888aabbbb99bcddfdca9aaa9998868788999789a9aaaaaaacbddabb9|+10 Pos|ooo ooo o oooooooooo oo oooooooo |Pos Clk| + +- |Clk +---------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:30.003 2003 Sep 26 2003 Sep 26
Latitude 69-26-17 N
Longitude 132-59-39 W
IGS Site Log
Very evident as data gaps ("-"), various "C", "I", "m" and "M" slips, and clock resets for nearly 2.5 hours.
Input RINEX file : tukt2690.03o input RnxNAV file : tukt2690.03n SV+------------------------------------------------------------------------+ SV 2| _++o;Iooooooo+++ ++;;ooooooooooo++ | 2 3|++ ++2oooooooooooo++ +++ooooooooo| 3 8|oooo+m_ __----ooo++ +++oooooooooo| 8 10|+ m+oooooIooooo+m _++oooooooooo++| 10 11|+ooooooooo++ _--oooooooMI--IC+ m| 11 15|o+++ _+ooooooooooooooo++ _++ooooo| 15 18|oooooo++ _m+ooooooooooooo+++ _++;o| 18 21| _+IIoIooooooooooo++ ++ooooooo++| 21 26|ooooooo++ __+oooooooooo++ _-ooooo| 26 27|o++_ _+Io2oooo+++ ++oooooooooooooo| 27 28|oooooooooo++ ++ooooooo+++ _---ooo| 28 29|ooooo+m_ _Io;oooooooo++ _++ooooooo| 29 31|oo;+m_ _---ooooooooo+++ _+ooooooo| 31 23|+oooooooo++ _--oooooooooooooMCC _| 23 7|++ooooooooooooo++ _++oooII----_ +| 7 9|_-ooooooooooooo++ ++oooooooo+++ | 9 14| ++;oooooooo+_ ++ooooooooMI--IC+^ | 14 5| ++oooooooooooooo+^ _---Cm----++ | 5 20| +++ooooooo++ m+ooMI----Iooooo+m | 20 4| ++oooooooooooo+m _-----ooooooom+ | 4 30| _+oooooooooooooIm+ ++-----Ioo++ | 30 24| ++oooooooooooooo++ _+oooooooooom+ | 24 25| _++oooooooo2m+ _++MI----IooooI2m^ | 25 6| ++ooooooooo;ooooo+m +++oooooo+m | 6 1| ++ooooooom+ _-----ooooooooooom+ | 1 17| ++oooooooooooooo+m ++;ooooooom+ | 17 13| ++ooooooo++_ _--oooooooooooooom+ | 13 16| _++oooIooooooo++ ++ooooooooooo+m | 16 -dn| 11 5c75 |-dn +dn| 1 11221 1ccccc7c 22 |+dn +10|acaa987888888899889aabbbb99acddedcaaaaaa998878789999789a9aaaaabbcbddbbb9|+10 Pos|ooo ooo oooooooooooooo oooooooooooo o|Pos Clk| ^--^^-^ |Clk +|--------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:29.996 2003 Sep 26 2003 Sep 26
Latitude 71-59-25 N
Longitude 125-14-59 W
IGS Site Log
Evident as "I", "M" and "m" slips, and clock resets but only for a short duration.
Input RINEX file : sach2690.03o input RnxNAV file : sach2690.03n SV+------------------------------------------------------------------------+ SV 2| __-oooooooooo+_ _+ooooooooooooom+ | 2 3|++_ __mooooooooooo++_ _moooooooooo| 3 8|oooo+m _-------o++_ ++oooooooooo| 8 10| +Ioooooooooooo+_ _+Ioooooooooo+_| 10 15|oom_ ++;ooooooooooooo+_ _+oooooo| 15 18|oooo;Im_ +1oooooooooooooo+_ _++oo| 18 21| _+oooooooooooooo+m _++oooooo1+^| 21 23|+oooooooo+_ __-oooooooooooooo-_ _+| 23 26|oooooo;+_ _+Moooooooooom+ _-moooo| 26 27|oIm_ _+oooooo;o+_ _++ooooooooooooo| 27 28|oooooooooo+_ _++2oooooo+m_ _---ooo| 28 29|ooooo++ _++oooooooooo++ _+ooooooo| 29 31|oooo+_ _---ooooooooo+_ _+ooooooo| 31 11|+ooooooooo+m_ __-ooooooooImoo+_ +| 11 7|^+oooooooooooooom_ _++oooo-Ioo+_ _| 7 9|_--ooooooooooo++_ ++ooooooooom+ | 9 14| ++oooooooo+m_ _+oooooooooImooom_ | 14 5| _+oooooooooooooo+_ __---mI---I+_ | 5 4| _+ooooooooooooo+_ _+oooooooooo++ | 4 20| _+oooooooom+_ _moooImooooooooo+_ | 20 30| _+ooooooooooooo++_ +I-mooooooom_ | 30 24| ++ooooooooooooo+_ ++ooooooooo+m_ | 24 25| _++ooooooooo+_ ++oMIoooooooooo+_ | 25 6| ++oooooooooooooo+_ _++ooooooom+_ | 6 1| _++ooooooom+_ ++oooooooooooooo+m | 1 17| _+oooooooooooooo+m_ _++oooooooo+_ | 17 13| _++ooooooom+_ _++oooooooooooooom_ | 13 16| _++oooooooooo+m_ _+oooooooooooo+_ | 16 -dn| 11 1 |-dn +dn| 1 1 1111311 11 cc111 221 |+dn +10|bcbaa87799878898889aababb8a9ddddebbabaaa98987888899988aaa9ab9bcaccddbbb9|+10 Pos|ooo o ooooo o oo o ooooooooo |Pos Clk| ^- |Clk +|--------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:29.999 2003 Sep 26 2003 Sep 26
Latitude 70-44-11 N
Longitude 117-45-39 W
IGS Site Log
Evident as "I", "C", "m", and "M" slips, clock resets, and data gaps for some satellites for nearly two hours.
Input RINEX file : holm2690.03o input RnxNAV file : holm2690.03n SV+------------------------------------------------------------------------+ SV 2| _-Io;oooooom+_ _+ooooooooooooo++ | 2 3|++_ ++o;ooooooooo++ ++oooooooooo| 3 8|ooo;o+_ _-----o;;++ _+oooooooooo| 8 10| __-oooooooooooo+_ ++;;oooooooo1_| 10 11|+oooooooooo+_ _+ooooooooM----_ _+| 11 15|o++_ _+Moooooooooooo22+ _--ooooo| 15 18|oooo;+^ _-o;oooooooooooo++ _++;o| 18 21| _+ooooooooooooooom_ _++ooooo;+m_| 21 26|ooooooI+_ _-2;ooooooooo++ _--;ooo| 26 27|;I+_ _+ooooooo++_ __-;oooooooooooo| 27 28|oooooooooo++ ++;oooooo++ _---ooo| 28 29|oooI;++ _mooooooooo;o1+ _+ooooooo| 29 31|oooo+_ _---ooooooooo+_ __m;oooooo| 31 23|+ooooo;2++_ _--ooooooooooooo--_ _+| 23 7|+1ooooooooooooo1+_ _+Moooo----__ _| 7 9|_-Iooooooooooom+_ _+oooooooooo+_ | 9 14| ++;ooooooo++ _+oooooooooICC-I+_ | 14 5| _+o;oooooooooooo+_ __--------m+_ | 5 4| _+ooooooooooooo+_ __--Coooooo;++ | 4 20| _+oooooooo++_ _++ooICCICoooooo++ | 20 30| ++oooooooooooo2+_ _++M---Iooo++_ | 30 24| _+oooooooooooooo++ _+ooo;ooooo+_ | 24 25| __+oooooooo++_ _++oICCICooooo;;+_ | 25 1| _++ooooooo++ _--moooooIoooooo++_ | 1 6| _-oooooooooooooo+m _++ooooooo++ | 6 13| _++ooooooo+__ _+oooooooooooooo+_ | 13 17| _--oooooooooooooo+_ +Mooooo;;++_ | 17 16| ++oooooooooom+ _-o;o;oooooooo+_ | 16 -dn| 11 4451 |-dn +dn| 1 1 1 1111132 111c56cc1 1 11111 |+dn +10|bbbaa97798878898889aabbbaaaaddddec9bbbaa98987898899888aa99aa9bbaccccbba9|+10 Pos|ooo o ooooo oo oo oooooo |Pos Clk| ^--^- |Clk +|--------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:29.998 2003 Sep 26 2003 Sep 26
Latitude 52-11-47 N
Longitude 106-23-53 W
IGS Site Log (not an IGS station)
Evident as data gap, "C", "I", "m", "M" slips, and clock resets for nearly 3 hours.
Input RINEX file : sask2690.03o input RnxNAV file : sask2690.03n SV+------------------------------------------------------------------------+ SV 2| _++oooo1m_ __--oooooooooooooom+ | 2 3|+ _-----oooooo+m_ _++ooooooooooo+| 3 7|ooooooooooooooooomm ______ _++| 7 8|ooooooo+_ _+++++_ _moooooooooo| 8 10| _+oooooooooooooo+m_ _++oooooo+m_| 10 11|ooooooooo++ ^+oooooMm-----__ _moo| 11 13| _+m+ooo++_ _+Iooooooooooooooom+ | 13 15|_ _+oooooooooooooooo++_ __m++m++| 15 18|____ _+oooooooooooooooooom_ __| 18 26|ooooooo++_ ++oooooooooooo++ _m+oo| 26 27|oooo+_ ______ _+oooooooooooooo| 27 28|oooooooooooom+ ______ _+oooooo| 28 29|oooooo+m _moooooooooooo+_ _+ooooo| 29 31|ooom+ ++oooooooom+_ ++oooooooooo| 31 23| ______ __-ooooooooooooooII---_ | 23 9| _+oooooooooooo+m __-ooooooooo++ | 9 4| +moooooooooooooo+m_ __--ooom++_ | 4 20| _m+oooooom_ ++MI---ICIoooooom+ | 20 5| ++ooooooooooooo--_ __--------_ | 5 14| _++++__ _+ooooooooooMmI-----+ | 14 24| _mooooooooooooooooo+_ _++m++m_ | 24 30| _++oooooooooooo+m_ _moMI-----Im_ | 30 17| _++ooooooooooooooooom+ ______ | 17 6| _++ooooooooooooooo+m_ _+m+oo+m_ | 6 25| __++o++m_ _moooMmI--ICIooooom+_ | 25 1| __+m+m+_ _---CMooooooooooooo+_ | 1 21| _m+ooooooooooooooooom_ _____ | 21 16| _++ooooooo++_ _----ooooooooooom_ | 16 -dn| 1 4cc44 |-dn +dn| 1 1 1 1 1cccccc6c |+dn +10|88888787677777777889988899aaaabcb9aaa99888888777788799788aa8789999aaa989|+10 Pos|o oo o oo o ooo oo oo |Pos Clk| ^--^^+-- |Clk +|--------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:29.997 2003 Sep 26 2003 Sep 26
Latitude 74-41-26 N
Longitude 94-53-35 W
IGS Site Log
Evident as complete tracking failure. Receiver did not recover and had ot be reset.
Input RINEX file : reso2690.03o input RnxNAV file : reso2690.03n SV+------------------------------------------------------------------------+ SV 2| ^+oooooooooo+++ _------CCCCo| 2 3|oomm __-ooooooooooo++ _----| 3 8|ooooom+ ++oooooooooo++ __--| 8 10| _+ooooooooooooooom+ __------| 10 11|ooooooooooooom+ __+ooooooooI----_ | 11 15|oo++_ _--oooooooooooooomm __| 15 18|ooooo+++ _-----;oIIoooooooom+ | 18 21| ++ooooooooooooooo+m __----| 21 23|ooooooooo+++ _++ooooooooooooooI--_ | 23 26|oooooom+^ _+oooooooooooooom+ | 26 27|oo++ __+oooooooooo+^ __------| 27 28|oooooooooooo++ __-;oooooooo++_ | 28 29|ooooo++ ++ooooooooooooomm+ _| 29 31|ooooo+m+ _----oooooooom+ _-| 31 7|_m+oooooooooooooooom+ _m+;ooooI----_ | 7 9| _--ooooooooooo+m_ _1ooooooooooooI__ | 9 14| ++ooooooooo++_ _+oooooooooI-------_ | 14 20| _m+ooooooooooom+_ _++oI------------__ | 20 5| ++oooooooooooooom_ __-------------_ | 5 4| _mooooooooooooooo+m_ _------------_ | 4 30| _++oooooooooooo+m^ _+oI-----------__ | 30 24| _++ooooooooooooooom+_ __-----------__ | 24 25| _++ooooooooo+++ __+I---------------_ | 25 1| ^+oooooooooo++_ _----------------| 1 13| _++oooooooooo2+ _-------------| 13 6| ++oooooooooooooo+m_ __------------_| 6 17| ^+oooooooooooooooom+ __--------| 17 16| ++ooooooooooom+ _-------------| 16 -dn| 1 1cccccccccccccc88999|-dn +dn| 1 121111 1 1 11cccccccccccccccca9aa|+dn +10|bbbaa9767888888988899aabbaaaaaabdddcccabbbaaa99987899888878aaaaaa9aababb|+10 Pos|oooo oooo oooooooo o |Pos Clk| ^^^^^^^^^^^^^^^---- |Clk +|---------|---------|---------|---------|---------|---------|---------|-+ 00:00:00.000 21:26:29.996 2003 Sep 26 2003 Sep 26
Latitude 82-29-39 N
Longitude 62-20-25 W
IGS Site Log
Evident as a short data gap, "I" and "M" slips, and short period clock resets for a period of about an hour.
Input RINEX file : alrt2690.03o input RnxNAV file : alrt2690.03n SV+------------------------------------------------------------------------+ SV 2| _+oooooooooo+m_ _++ooooooooooooom+| 2 3|ooom+ _--ooooooooom+ _+oooooooooo| 3 8|ooo+m_ ^+ooooooooooom+ ++oooooooo| 8 10| ++oooooooooooo+m+ _+I;oooooooom+_ | 10 11|+oooooooooooom+ _++oooooooM-I++ _+| 11 15|ooo++ _----ooooooooom+ _--ooooooo| 15 16| ++oooooooooom+ ++oooooooooooomm_ | 16 18|ooooo++_ _---oooooooooo++ ++ooooo| 18 21|+ _+oooooooooooo++ ^+moooooooooom| 21 23|ooooooooo+m_ __IoooooooooooI-+ _+oo| 23 26|ooooo++ ++oooooooooooom+ __--oooo| 26 27|om+ +mooooooooooo++ _+;ooooooooooo| 27 28|oooooooooo+m __--ooooooooom+ _mooo| 28 29|ooom+ ++oooooooooooomm _++ooooooo| 29 31|oooooom+ _+ooooooooo;m+ _-------o| 31 9|_+oooooooooo++_ _+ooooooooooM-Im | 9 7| _++oooooooooooo++_ _++oooooM-Io+m_ | 7 14| _+oooooooooom+ ++ooooooM-Iooo++_ | 14 20| m+ooooooooooo+m +moIIIooooooo++ | 20 5| +mooooooooooo++ _----------Moom+ | 5 4| _++oooooooooooom+ +-Ioooooooo;++ | 4 30| ++oooooooooo++_ ++IIIooooooooo+m | 30 25| m+oooooooooom+ ++-Iooooooooooo++ | 25 24| _+ooooooooooooom+ ^+oooooooooo+m_ | 24 1| ++ooooooooooo++ _+oooooooooooo++ | 1 13| ++ooooooooooo++ ++ooooooooooo+m_ | 13 6| +mooooooooooo+++ m+ooooooooooo+m | 6 17| ++oooooooooooo;m_ _++oooooooooo+_ | 17 -dn| |-dn +dn| 11211 11 1ccc1 1 1122111 |+dn +10|bbbb9977888898999999abbaaabbccddccbbbbaaaa88789a988899aabab9baabccddbccb|+10 Pos|ooooo ooooooooooooooooooooo ooo o ooooooooooo|Pos Clk| ^^^ |Clk +---------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:30.000 2003 Sep 26 2003 Sep 26
Latitude 56-32-13 N
Longitude 61-41-19 W
IGS Site Log
Evident as long data gaps for some satellites, "C", "M", "I" and "m" slips, and clock resets for about 3 hours.
Input RINEX file : nain2690.03o input RnxNAV file : nain2690.03n SV+------------------------------------------------------------------------+ SV 2|-_ _+m++__ _---ooooooooooooooo-| 2 15|+m+ _+oooooooooooo1m_ __--oooooooo| 15 3|oo++_ _++ooo+m+_ _+ooooooooooooo| 3 8|ooooo1m_ __+ooooooooom+ _++oooooo| 8 11|oooooooooooo2+_ _++ooooCCC_ _+ooo| 11 16| _+++++m__ _-----oooooooooooo++_ | 16 18|1mm+ _+oooooooooooooooo+_ +++Io| 18 21| _+oooooooooooooom_ ^+ooooooo+m_ | 21 23|ooooo+m+ _+ooooooooooooCCCC+ _++o| 23 26|oo;+__ _--oooooooooooooo++_ _++;| 26 27|oooo+_ _++oMooooo+m+ ^+oooooooooo| 27 28|ooooooooooooo+_ _++ooooom+_ _--o| 28 29|oo+m ++ooooooooooooooom+ _m+IIo| 29 31|oooooo2+_ ___++++_ _+oooooooooo| 31 7|__+oooooooooooooooo-_ +++++++_ | 7 9| ^+oooooo2+_ _+ooooooooooooooCC | 9 20| _--ooooooooooo+m^ _------MCIoom_ | 20 14| ++++o+m+ _+ooooooooMCCCCCCCm__ | 14 4| _+ooooooooooooooooo-_ ____+C__ | 4 5| _+ooooooooo++_ __-------Cm--ICC+ | 5 24| _++oooooooooooooooo--_ ___++++_ | 24 1| _+oooooooooom+ _----oooooooooo+_ | 1 30| _+ooooooo2++_ _+ooooI--CCCCCI+m+ | 30 13| _-oooooooooo+m_ _m;oooooooooo2+_ | 13 25| _+m+++_ _mooM-------Ioooooo-__ | 25 10| _+ooooooooooooooooo+_ _++++m+_ | 10 17| ++oooooooooooooooo+_ +++ooo++m | 17 6| _++oooooooooom+_ __------ooooo+m_ | 6 -dn| 2333433 |-dn +dn|1 1 1 11 111 143445555c 1 1 1|+dn +10|ca97787677778788888999898aa99aaaaacca899978888876677888887899ab99aa99acc|+10 Pos|o o oo o oo oo o oo|Pos Clk| --------- |Clk +|--------|--------|--------|--------|--------|--------|--------|--------+ 00:00:00.000 23:59:29.986 2003 Sep 26 2003 Sep 26