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TEQC 14 Mar 2002 Release Notes

Select your favorite build of teqc in the usual way, but be sure to save your current version in case any new bugs show up. Other information on these and other minor bug fixes and enhancements can be found at 2002 Mar 14 bug fixes and at 2002 Mar 14 release log, plus any notices since the last release you have:

If you are unfamiliar with teqc, please also see the teqc homepage. Indexes for this release are:

Recall that all teqc email traffic will now be handled via a teqc on-line email forum, teqcunavco.org, to which users can subscribe/unsubscribe. This will continue to be an unmoderated email forum.

--Lou Estey

General Remarks:

Hopefully this newest teqc won't seem too much different from the previous versions except for new functionality (see below) and quite an extensive set of bug fixes or enhancements. Actually, though, there were some fairly extensive code redesigns, especially with regards to RINEX reading and writing--even since the beta(2) 28 Nov 2001 version. These were necessary to allow for additional header elements that will be defined in RINEX version 2.20, and allow for more consistent logic control in RINEX operations involving metadata editing, file splicing, and time windowing. Consequently, please be on the alert for any result that seems questionable or wrong, even if it had been reported to be found and fixed in the past. There might be a few minor details that have slipped though undetected.

However, the latest functionality in teqc has been put through many tests, especially by the manufacturers. A brief (and very incomplete) list of acknowledgements to:

  • Brian Frohring (Trimble): DAT and RT17 formats, Trimble 4700 BINEX
  • Peter Large and Tom Coates (Trimble): Trimble 4700 BINEX firmware
  • Tim Peterson (Trimble): Trimble 4700 BINEX testing
  • Sergei Podshivalov (Ashtech): R- and U-file formats, Ashtech micro-Z BINEX firmware
  • Robert Snow, Jon Siegrist, and Xinhua Qin (Ashtech): numerous other Ashtech technical issues
  • James Stowell (Leica): LB2 format, testing
  • Kevin Dixon (Leica): MDB format, testing
  • Erwin Rapatz, Elmar Brockmann, Niklas Elsaesser, Frank Pache, Barry Jernigan, and others (Leica): numerous Leica technical odds and ends
  • Michel Gonthier (Canadian Marconi Corp): Allstar technical support
  • Razmik Khachikyan and Dave Stowers (JPL): translation testing on DEC Alpha
  • Herb Dragert (PGC): various testing, collection of special datasets
  • John Beavan (GNS): various testing
  • James Foster (SOEST): R-file translation testing
  • Michael Scharber (SOPAC/UCSD): various testing
  • Keith Stark (dukester.com): R-file translation testing on SCIGN data
  • Doug Hogarth (niceties.com): various testing on Windows platforms
  • Ole Hansen: qc testing on Linux x86
  • Doug Hunt (GST & COSMIC/UCAR): BINEX library
  • Chris Rocken, John Braun, Teresa Van Hove (GST/UCAR): issues of all sorts
  • Angie Moore (JPL & IGSCB): IGS issues
  • and especially Werner Gurtner (AIUB/U. Berne): RINEX, IGS issues

Translation of Binary Formats:

The following additional formats can be translated with teqc:

  • Ashtech CGRS Z-12 R-file     -ash r (usually optional)
  • Ashtech CGRS micro-Z U-file     -ash u (required)
  • Ashtech CGRS micro-Z BINEX     -binex (suggested)
  • Trimble 4700 BINEX     -binex (suggested)
  • Leica System 500 LB2     -leica lb2 (usually optional)
  • Leica MDB     -leica mdb (usually optional)

Teqc now supports the reading of the following binary MET data:

  • Trimble DAT (records 9, 20, and 16-254)
  • Trimble RT17 (0x57-3)
  • Ashtech D-file
  • Ashtech R-file (record 6)
  • Ashtech U-file (D-record)
  • Leica DS*.met file
  • Leica LB2 (record 0x10)
  • Leica MDB (record 14)
  • BINEX (record 0x7e) (e.g., from Ashtech micro-Z, Trimble 4700)

Translation of Trimble DAT and RT17 formats now uses a flag interpretation identical to or very close to what Trimble's DAT2RIN program uses. The main result is that you may occasionally now get pseudorange observables for an SV even if there are no phase observables yet (as sometimes occurs at the beginning or ending of the tracking of the SV).

Translation of CMC Allstar binary data has reverted back to the original methodology where the time tag reported in RINEX OBS is the "predicted GPS time" of record 23. (Attempts to remove the integer number of 175-ns receiver clock resets between successive epochs proved unsatisfactory.) Thus the translation to RINEX does not technically conform to RINEX specifications, where the time tags and observables should be in receiver time. No further changes are planned.

For users of the clockprep program (which converts a RINEX OBS file from receiver time to GPS time were millisecond receiver clock resets are present): you can now directly translate into GPS time by including the +GPS_t flag. (This only works when converting from raw data to RINEX.)

RINEX Editing:

Earlier versions of teqc would only allow the editing of RINEX header fields which were present in the original file. For example, the -O.int option would only work if there were already an INTERVAL header line in the RINEX OBS file. Insertion of optional header fields (such as the INTERVAL header line) will now do done by using the appropriate option, even if missing from the original RINEX file:

  • -O.mn      RINEX OBS monument number
  • -O.int     RINEX OBS observation interval
  • -O.leap    RINEX OBS leap seconds since 6.0 Jan 1980
  • -N.a       RINEX NAV ionosphere alpha model parameters
  • -N.b       RINEX NAV ionosphere beta model parameters
  • -N.UTC     RINEX NAV UTC time model parameters
  • -N.corr    RINEX NAV correction to system time
  • -N.leap    RINEX NAV leap seconds since 6.0 Jan 1980
  • -M.mn      RINEX MET monument number

RINEX NAV Metadata:

It was discovered that Trimble firmware had on occasion in the past accidently reversed the UTC model parameters A0 and A1. Apparently, the first version of teqc had been looking at one of these reversed situations, so the translation of most UTC model parameters A0 and A1 from Trimble DAT files has been wrong since that time. This has been fixed, and using teqc as a null filter on any existing RINEX GPS NAV file:

  •   teqc RINEX_NAV_old > RINEX_NAV_new

should correct the ordering of A0 and A1.

Teqc now allows multiple occurances of the optional ION ALPHA, ION BETA, and/or DELTA-UTC: A0,A1,T,W headers lines in a RINEX GPS NAV file header, since this isn't forbidden by the RINEX specification and there is a growing interest in having these model parameters available. For those interested, the trick is to get the parameter lines into the RINEX header, since during translation teqc will only put in those values found prior to the first navigation message. Two new options, +dump_ion and +dump_utc write out all encountered ion and UTC model parameters (to stderr, or whatever file has been specified with +err). The ion and UTC parameters lines can then be extracted, sorted, and so, and used to create a header-only RINEX GPS NAV file (left as a

n exercise for the user). This file can be spliced with the normal navigation file: 
  •   teqc RINEX_NAV_header_only RINEX_NAV_normal > RINEX_NAV_new

to create a RINEX GPS NAV file with all ion and UTC parameters available from the raw data.

QC of LEO or Other Fast Kinematic Data:

A new option has been added to allow for quality checking of LEO ("low earth orbiting") data or other situations with fast kinematic data: +eep = "every epoch point-position". A point-position is attempted at every epoch.

With LEO data, you will probably want to lower the apparent horizon angle and the elevation mask. For example, with CHAMP data (orbit elevation ~440 km), the apparent horizon is -20.7° from the local "horizontal" plane. Decreasing this to -25° (for an even number of 5° increments):

  •   teqc +qc +eep -mp_bins 23 -ion_bins 23 -sn_bins 23 -set_hor -25 -set_mask -25 -iod_jump 400000 cham1550.01o > cham1550.qc

where the number of elevation bins for multipath and so on was increased to 23 (again for even 5° increments from +90° to -25°), and the IOD slip criterion was increased by 3 orders of magnitude (to account for the fast LEO motion)--and assuming the corresponding RINEX GPS NAV file cham1550.01n is in the same directory, and so on, as usual.

Some minor formatting changes were also done in the qc report to correctly allow for negative horizon and elevation mask angles.

IGS Receiver, Antenna, and Radome Designations:

The receiver and antenna (with or without radome) designations supplied with the -O.rt and -O.at options are tested against the current (5 Mar 2002) IGS designations (in the ASCII file rcvr_ant.tab). To obtain a complete listing of the current IGS ASCII codes, execute

  • 	teqc ++igs
 

Last modified: 2019-12-24  02:29:43  America/Denver