[teqc] helpful tip of week 2033

Lou Estey lou at unavco.org
Wed Dec 26 16:12:43 MST 2018


This week's tip: reasons 7-11 that navigation messages might be discarded

(continued from the last tip of the week)

7) For any given SV, only the first navigation message found where ToC == ToE for that
ToC/ToE epoch is kept (except Galileo). Depending on the situation, it is entirely possible
for "duplicate" navigation messages to show up, such as raw data from certain receivers
(depending on receiver type, firmware, configuration settings, etc.). Rather than comparing
all fields between navigation messages, teqc only compares the ToC/ToE epochs for any
given SV to indicate duplication -- with an exception for Galileo made in teqc 5 Nov 2018.

The change for Galileo now also requires that the "Data sources" field indicate the same
navigation message, i.e. I/NAV or F/NAV, to indicate duplication. Stated a different way,
for any specific Galileo SV for a given ToC/ToE, the first Galileo I/NAV message with
ToC == ToC is kept and also the first Galileo F/NAV with ToC == ToE is kept. (*)

8) Starting 8/9 Nov 2018 -- this is part of the 2018Dec12 version recently released --
both GPS CNAV and CNAV2 and QZSS CNAV and CNAV2 are (most likely) eliminated by default.
This applies for both translation and qc operations. A multi-pronged approach is used
to try to do this (since for GPS CNAV/CNAV2 there may not be any definitive indicator),
so for GPS the ToC/ToE is also used if all else fails; see tip of week 1973,
https://postal.unavco.org/pipermail/teqc/2017/002363.html, i.e. a GPS ToC/ToE which occurs
at times other than XXh:00m:00s and other than N*16 seconds prior to XXh:00m:00s, where
N = 1, 2, 3, 4, ..., 224 (the so-called "backticked" GPS LNAV navigation messages) are
assumed to not be GPS LNAV messages and these navigation messages are discarded. (**)

9) For qc point-positioning starting 5 Nov 2018, Galileo F/NAV messages are eliminated
from being used. (Again, this is part of the 2018Dec12 version.) Related to this,
pseudoranges from Galileo E5a and E5a+b are also not used for point-positioning, since
use of these signals require use of the Galileo F/NAV messages. There is no option to
override this behaviour. (***)

10) For qc point-positioning starting Sept 2015, by default, navigation messages of SVs
indicated as unhealthy are not used. This can be overridden by using '+unhealthy' option
(= "use ephemerides with unhealthy status"), but doing so is generally not advised.

11) For qc point-positioning, for any GPS SV, the backticked LNAV navigation message (if
one occurs) with the largest N = 1, 2, 3, 4, ..., 224 (i.e. with a ToC/ToE earliest in time,
since backticked LNAV are for N*16 seconds before the hour) take precedence over the hourly LNAV
(if present), as soon as the backticked LNAV is detected. Thus, for SV zz, its LNAV message
at (XX-1)h59m44s (N = 1) takes precedence over its LNAV message at XXh00m00s, unless an LNAV
message at (XX-1)h59m28s (N = 2) occurs, in which case that LNAV messages takes precedence,
and so on. If reading GPS RINEX navigation file(s) as input, this GPS LNAV sorting/discarding
occurs before the qc is started. If reading raw data as a file or via stdin (e.g. a stream),
then the replacement occurs as the backticked LNAV messages are encountered.

Happy teqc-ing!

cheers,
--lou

* Either Galileo I/NAV or F/NAV messages can be eliminated by using the new '-eph' option
with the proper arguments.

** GPS CNAV or CNAV2 messages which occur 30 or 25 minutes prior to XXh:00m:00s or QZSS
CNAV or CNAV2 messages (only from translation) can be included by using the new '+eph' option
with the proper arguments -- but be advised you should really know what you are doing to request
and use these and be advised that certain broadcast ephemeris elements specific to CNAV/CNAV2
will be missing.

*** Related to (9): Pseudoranges from Galileo E6 are also eliminated from being used for
point-positioning during qc, since E6 requires uses of its own C/NAV navigation message.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Louis H. Estey, Ph.D.               office: [+001] 303-381-7456
UNAVCO, 6350 Nautilus Drive            FAX: [+001] 303-381-7451
Boulder, CO 80301-5554              e-mail:   lou unavco.org

"If the universe is the answer, what is the question?"
                                                -- Leon Lederman
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Past helpful tips:

week 1894: using teqc config files - https://postal.unavco.org/pipermail/teqc/2016/002067.html
week 1895: qc of high-rate data - https://postal.unavco.org/pipermail/teqc/2016/002071.html
week 1896: UNIX/Linux shells for Windows - https://postal.unavco.org/pipermail/teqc/2016/002072.html
week 1897: '-' vs. '+' teqc options - https://postal.unavco.org/pipermail/teqc/2016/002076.html
week 1898: auto-identification of formats - https://postal.unavco.org/pipermail/teqc/2016/002092.html
week 1899: auto-identification vs. format flags - https://postal.unavco.org/pipermail/teqc/2016/002096.html
week 1900: square brackets in options - https://postal.unavco.org/pipermail/teqc/2016/002105.html
week 1901: using option '+mds' - https://postal.unavco.org/pipermail/teqc/2016/002108.html
week 1902: qc results w/ problematic nav messages - https://postal.unavco.org/pipermail/teqc/2016/002113.html
week 1903: '-no_orb[it]' and '-no_pos[ition]' options - https://postal.unavco.org/pipermail/teqc/2016/002115.html
week 1904: '-week' option - https://postal.unavco.org/pipermail/teqc/2016/002117.html
week 1905: using '+bcf' for XYZ/geodetic conversion - https://postal.unavco.org/pipermail/teqc/2016/002126.html
week 1906: the '+v[erify]' option - https://postal.unavco.org/pipermail/teqc/2016/002128.html
week 1907: '+C2', '+L5', "+L6', '+L7', '+L8', '+all' options - https://postal.unavco.org/pipermail/teqc/2016/002130.html
week 1908: getting RINEX doppler and L2 - https://postal.unavco.org/pipermail/teqc/2016/002131.html
week 1909: using paths w/ file names - https://postal.unavco.org/pipermail/teqc/2016/002132.html
week 1910: the (un)importance of file names - https://postal.unavco.org/pipermail/teqc/2016/002133.html
week 1911: notices, warnings, and errors - https://postal.unavco.org/pipermail/teqc/2016/002134.html
week 1912: the '-max_rx_SVs' option - https://postal.unavco.org/pipermail/teqc/2016/002137.html
week 1913: the end of '++igs' and '+igs' - https://postal.unavco.org/pipermail/teqc/2016/002140.html
week 1914: splicing together RINEX files - https://postal.unavco.org/pipermail/teqc/2016/002144.html
week 1915: using '-O.int' and '-O.dec' - https://postal.unavco.org/pipermail/teqc/2016/002145.html
week 1916: '+doy' option - https://postal.unavco.org/pipermail/teqc/2016/002146.html
week 1917: '-tbin' and '-ast' options - https://postal.unavco.org/pipermail/teqc/2016/002152.html
week 1918: mp12 RMS before/after Oct 2013 - https://postal.unavco.org/pipermail/teqc/2016/002158.html
week 1919: the global windowing options - https://postal.unavco.org/pipermail/teqc/2016/002159.html
week 1920: '-M.dec' and '-N.dec' options - https://postal.unavco.org/pipermail/teqc/2016/002163.html
week 1921: combining time filtering options - https://postal.unavco.org/pipermail/teqc/2016/002176.html
week 1922: helping me (or someone else on the list) help you - https://postal.unavco.org/pipermail/teqc/2016/002187.html
week 1923: the "build" line - https://postal.unavco.org/pipermail/teqc/2016/002190.html
week 1924: the qc '-w[idth]' option - https://postal.unavco.org/pipermail/teqc/2016/002193.html
week 1925: qc with explicit time windowing - https://postal.unavco.org/pipermail/teqc/2016/002194.html
week 1926: the '+rx_state' option - https://postal.unavco.org/pipermail/teqc/2016/002200.html
week 1927: the '-O.sum' option - https://postal.unavco.org/pipermail/teqc/2016/002204.html
week 1928: the '+meta' and '+mds' options - https://postal.unavco.org/pipermail/teqc/2016/002206.html
week 1930: more on '-O.sum' - https://postal.unavco.org/pipermail/teqc/2017/002207.html
week 1931: the '-O.s[ystem]' option - https://postal.unavco.org/pipermail/teqc/2017/002208.html
week 1932: leap seconds - https://postal.unavco.org/pipermail/teqc/2017/002215.html
week 1936: what you can (and shouldn't) do in a RINEX obs file - https://postal.unavco.org/pipermail/teqc/2017/002229.html
week 1938: the '+psp' option - https://postal.unavco.org/pipermail/teqc/2017/002231.html
week 1939: the '+diag' option - https://postal.unavco.org/pipermail/teqc/2017/002235.html
week 1951: '-n_<system>' and SV filtering options - https://postal.unavco.org/pipermail/teqc/2017/002277.html
week 1953: more with '+diag' option - https://postal.unavco.org/pipermail/teqc/2017/002287.html
week 1954: using '+diag' output to split raw files - https://postal.unavco.org/pipermail/teqc/2017/002290.html
week 1955: current qc notation - https://postal.unavco.org/pipermail/teqc/2017/002302.html
week 1956: the '+qcq' option - https://postal.unavco.org/pipermail/teqc/2017/002304.html
week 1957: using Trimble formats - https://postal.unavco.org/pipermail/teqc/2017/002305.html
week 1958: ToC != ToE messages - https://postal.unavco.org/pipermail/teqc/2017/002310.html
week 1959: receivers vs. formats - https://postal.unavco.org/pipermail/teqc/2017/002311.html
week 1960: when the '-week' option is very wrong to use - https://postal.unavco.org/pipermail/teqc/2017/002314.html
week 1961: "less" is usually best - https://postal.unavco.org/pipermail/teqc/2017/002315.html
week 1962: using GPS L2C with teqc - https://postal.unavco.org/pipermail/teqc/2017/002316.html
week 1964: the '+eds' options - https://postal.unavco.org/pipermail/teqc/2017/002317.html
week 1965: handling RINEX comment lines - https://postal.unavco.org/pipermail/teqc/2017/002324.html
week 1966: the '+dUTC_p' options - https://postal.unavco.org/pipermail/teqc/2017/002331.html
week 1967: the strange position from '+meta' - https://postal.unavco.org/pipermail/teqc/2017/002355.html
week 1972: what shows up as metadata in RINEX headers - https://postal.unavco.org/pipermail/teqc/2017/002362.html
week 1973: GPS L2C navigation messages - https://postal.unavco.org/pipermail/teqc/2017/002363.html
week 1974: the '+ion_p' options - https://postal.unavco.org/pipermail/teqc/2017/002370.html
week 1975: the '+event' options - https://postal.unavco.org/pipermail/teqc/2017/002372.html
week 1976: options '+smtt' (default) vs. '-smtt' - https://postal.unavco.org/pipermail/teqc/2017/002374.html
week 1977: the reported interval with '+meta' for a RINEX obs file - https://postal.unavco.org/pipermail/teqc/2017/002377.html
week 1978: the '-N.dUTC' options - https://postal.unavco.org/pipermail/teqc/2017/002378.html
week 1979: the various qc elevation angles - https://postal.unavco.org/pipermail/teqc/2017/002383.html
week 1980: avoid in RINEX: Transit data - https://postal.unavco.org/pipermail/teqc/2017/002385.html
week 1981: avoid in RINEX: epoch flag = 6 - https://postal.unavco.org/pipermail/teqc/2017/002389.html
week 1982: avoid in RINEX: RCV CLOCK OFFS APPL = 1 - https://postal.unavco.org/pipermail/teqc/2018/002392.html
week 1983: don't count on in RINEX: receiver clock offset per epoch - https://postal.unavco.org/pipermail/teqc/2018/002393.html
week 1984: requirements for multiple target files/stdin - https://postal.unavco.org/pipermail/teqc/2018/002410.html
week 1985: default output for various input - https://postal.unavco.org/pipermail/teqc/2018/002412.html
week 1986: the '+latency' options - https://postal.unavco.org/pipermail/teqc/2018/002419.html
week 1987: the 'O.px and 'O.pg' options - https://postal.unavco.org/pipermail/teqc/2018/002422.html
week 1988: the '+relax' option - https://postal.unavco.org/pipermail/teqc/2018/002423.html
week 1992: the '+x_tilt' options - https://postal.unavco.org/pipermail/teqc/2018/002452.html
week 1993: GLONASS: slot and freq. chnl. numbers - https://postal.unavco.org/pipermail/teqc/2018/002453.html
week 1994: GLONASS: slot numbers > 24 - https://postal.unavco.org/pipermail/teqc/2018/002454.html
week 1995: GLONASS: signals - https://postal.unavco.org/pipermail/teqc/2018/002456.html
week 1996: GLONASS: broadcast ephemeris - https://postal.unavco.org/pipermail/teqc/2018/002457.html
week 1997: GLONASS: system time and broadcast time parameters - https://postal.unavco.org/pipermail/teqc/2018/002458.html
week 1998: qc: 'lite' vs. 'full' - https://postal.unavco.org/pipermail/teqc/2018/002470.html
week 1999: qc: the 'full' point-position and the antenna 'height' - https://postal.unavco.org/pipermail/teqc/2018/002474.html
week 2000: qc: what's a "complete observation"? - https://postal.unavco.org/pipermail/teqc/2018/002475.html
week 2001: qc: percentage of actual to expected complete observations - https://postal.unavco.org/pipermail/teqc/2018/002483.html
week 2014: qc: interpreting slips - https://postal.unavco.org/pipermail/teqc/2018/002521.html
week 2015: qc: loss-of-lock - https://postal.unavco.org/pipermail/teqc/2018/002524.html
week 2016: qc: observations per slip - https://postal.unavco.org/pipermail/teqc/2018/002526.html
week 2017: qc: multipath rms - https://postal.unavco.org/pipermail/teqc/2018/002527.html
week 2018: qc: signal-to-noise - https://postal.unavco.org/pipermail/teqc/2018/002532.html
week 2019: qc: the ASCII time plot - https://postal.unavco.org/pipermail/teqc/2018/002534.html
week 2020: qc: little known (but sometimes useful) options - https://postal.unavco.org/pipermail/teqc/2018/002535.html
week 2021: qc: qc full: the '-dn' and '+dn' ASCII time plot lines, part I - https://postal.unavco.org/pipermail/teqc/2018/002544.html
week 2022: qc: qc full: the '-dn' and '+dn' ASCII time plot lines, part II - https://postal.unavco.org/pipermail/teqc/2018/002554.html
week 2023: qc: point-position elevation restrictions - https://postal.unavco.org/pipermail/teqc/2018/002556.html
week 2024: qc: main "filtering" possibilities - https://postal.unavco.org/pipermail/teqc/2018/002557.html
week 2025: qc: expectations for teqc's PP in Solar Cycle 25 - https://postal.unavco.org/pipermail/teqc/2018/002558.html
week 2026: qc: when the antenna is moving (a lot) - https://postal.unavco.org/pipermail/teqc/2018/002564.html
week 2027: qc: direct quality check of raw data - https://postal.unavco.org/pipermail/teqc/2018/002569.html
week 2028: navigation message intervals and using '-tbin' - https://ls.unavco.org/pipermail/teqc/2018/002578.html
week 2029: the '-ns' and '-ne' time windowing options - https://ls.unavco.org/pipermail/teqc/2018/002579.html
week 2030: "no routine" messages in stderr - https://ls.unavco.org/pipermail/teqc/2018/002580.html
week 2031: why zero-length files that are created are left in place - https://postal.unavco.org/pipermail/teqc/2018/002581.html
week 2032: reasons 1-6 that navigation messages might be discarded - https://postal.unavco.org//pipermail/teqc/2018/002596.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://postal.unavco.org/pipermail/teqc/attachments/20181226/000bc7cf/attachment-0001.html>


More information about the teqc mailing list