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TEQC 22 Oct 1998 Release Notes

GPS/GLONASS enhancements

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. There are a number of significant issues relating to this IGEX98 release of teqc with GLONASS capability, indexed below. Other information on these and other minor bug fixes and enhancements can be found at 1998 Oct 22 bug fixes and at 1998 Oct 22 release log. If you are unfamiliar with teqc, please see the teqc homepage.

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

--Lou Estey


General Z-18 and GG24 translation issues

For translationing Z-18 or GG24 data with this version of teqc, the Z-18 or GG24 receiver must be run using the GPS time base (rather than the GLONASS time base). To translate an Ashtech fileset into RINEX:

	teqc -config cfg_file +nav GPS_RINEX_NAV,GLO_RINEX_NAV Bfile > mixed_RINEX_OBS
Details on the config file cfg_file (or the same options used directly on the command line) will be discussed below. First, note that the argument for the "+nav" option takes the two RINEX NAV filenames seperated by a comma (no whitespace, please!). The GPS RINEX NAV filename is assumed to occur first; the GLONASS RINEX NAV filename is assumed to occur second. (There are other ways of obtaining these RINEX files, but I'm just showing the simpliest way to get them.)

Also, this default mode does not apply pseudorange smoothing corrections to the C1, P1, and P2 observables. Also, the L1 phase value is obtained from the P1-code block (rather than the C/A-code block as is the usual with the Berne translator ASRINEXO); this default behaviour is equivalent to including the option "-Ashtech_CA_L1". To apply the pseudorange smoothing corrections:

	teqc +smooth +nav GPS_RINEX_NAV,GLO_RINEX_NAV Bfile > mixed_RINEX_OBS
To use the L1 value in the C/A-code block:
	teqc +Ashtech_CA_L1 +nav GPS_RINEX_NAV,GLO_RINEX_NAV Bfile > mixed_RINEX_OBS
To apply the pseudorange smoothing corrections and use the L1 value in the C/A-code block:
	teqc +smooth +Ashtech_CA_L1 +nav GPS_RINEX_NAV,GLO_RINEX_NAV Bfile > mixed_RINEX_OBS
Thus, four different styles of mixed RINEX OBS files can be generated with the main observables L1, L2, C1, P1, P2.

In order to successfully translate the Z-18 or GG24 GLONASS data into the RINEX OBS format, the frequency number of each GLONASS satellite must be known. If all goes well, this will be extracted from info in the E-file, whether or not converting this into the RINEX NAV files. Under extraordinary conditions (e.g. extremely short windows of data collection), the GLONASS navigation messages will be missing from the E-file, and the L1 and L2 GLONASS data will be translated incorrectly. In this case, you can supply the missing slot number to frequency number pairs in a small ASCII file, e.g.:

	15	4
	16	22
	17	24
	22	10
	9	6
Then supply this filename to teqc using the "-glonass_n" option:
	teqc -glonass_n slot_n_file { ...other option...} Bfile > mixed_RINEX_OBS


Z-18 details

When translating Z-18 B/E/S filesets, you will probably need to include the following options (either on the command line or via a configuration file):

	-ash d
	-max_rx_ch 18
	-max_rx_SVs 18
	+msec_phs_adj
were +msec_phs_adj activates removal of milliseconds phase jumps due to millisecond clock resets. (Note: This is not known to be needed for Z-XII data!) Additionally, include:
	+smooth
to add the pseudorange smoothing corrections to C1, P1, and P2.

When translating Z-18 stream data (containing observations in MPC records), you will probably need to include:

	-ash s
	-week #
	-max_rx_ch 18
	-max_rx_SVs 18
	+msec_phs_adj
where # is replaced by the appropriate GPS week number (or year:DOY or year:month:day) for the start of the data. Include +smooth to include the pseudorange smoothing corrections.


GG24 stream translation

When translating GG24 stream filesets (containing MBN or MCA records), you will probably need to include the following options (either on the command line or via a configuration file):

	-ash s
	-P
	-L2
	-max_rx_ch 24
	-max_rx_SVs 24
	+msec_phs_adj
which will remove milliseconds phase jumps due to millisecond clock resets. Additionally, include:
	+smooth
to add the pseudorange smoothing corrections to C1.


GPS/GLONASS QC

To QC RINEX data, use the usual:

	teqc +qc -plot {...other options...} mixed_RINEX_OBS
The option "-plot" (turn off plot file creation) is done because the processing software for the plot files, gt and qcview are not yet ready to handle the mixed GPS/GLONASS plot files (though Jim Johnson is actively working on this).

Like with the Ashtech Z-18 and GG24 translation (see above), you may need to supply a slot vs. freq. number information filename using the "-glonass_n" option.

If using the Berne RINEX file naming convention, i.e. the .YYO or .YYo, .YYN or .YYn, and .YYG or .YYg suffixes for the RINEX OBS, GPS RINEX NAV, and GLONASS RINEX NAV respectively; or .OBS or .obs, .NAV or .nav, and .GLO or .glo suffixes: teqc will automatically search for the matching RINEX NAV files using the supplies RINEX OBS filename(s). Or you can force teqc to read specific NAV filename(s), which can be GPS RINEX NAV and/or GLONASS RINEX NAV:

	teqc +qc -plot -nav RINEX_NAV1,RINEX_NAV2 {...other options...} mixed_RINEX_OBS

For now, GLONASS observations are processed using a qc-lite mode, regardless of whether or not a GLONASS RINEX NAV file is use. (Basically the information in the GLONASS NAV file, except for the frequency number for each GLONASS slot number, is ignored for now.)


initial OS builds for IGEX98

A limited number of initial teqc builds are being done now for the start of IGEX98 (uncompress/unzip as appropriate):

Last modified: Saturday, 10-May-2014 23:05:49 UTC

 

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