[teqc] helpful tip of week 2023

Lou Estey lou at unavco.org
Wed Oct 17 12:09:34 MDT 2018


This week's tip: qc: point-position elevation restrictions

Starting with the latest version, 2018Oct15, the elevation for each point position is
restricted to be between two threshold elevation values, a minimum and a maximum, and
if the PP's elevation is outside of this range, then the PP is rejected.  The default
values are a minimum of -500 meters and a maximum of 9000 meters from the WGS84 reference
ellipsoid, which cover all possible solutions on the surface of the Earth with a little
additional wriggle room.

Either of these thresholds can be modified with two new options:

-pos_h_min[m] #    to set a minimum elevation threshold value #, in meters, above the ellipsoid
                    (the default is -500 meters)

-pos_h_max[m] #    to set a maximum elevation threshold value #, in meters, above the ellipsoid
                    (the default is 9000 meters)

You can find these options in the new '+help':

[897] teqc +help | grep pos_h
                 -pos_h_min[m] #          set minimum height position solution to # meters (default = -500.0 m)
                 -pos_h_max[m] #          set maximum height position solution to # meters (default = 9000.0 m)

So, if you are using teqc (version 2018Oct15 and all versions thereafter) to qc data collected
on a platform that is at an elevation of more than 9000 meters, e.g. aircraft or LEO satellite,
then you will want to appropriately adjust at least the maximum elevation value on the qc command
line using the '-pos_h_max' option.

Any solutions which end up being rejected are tagged with a 'K' (= "solution convergence problem")
in the ASCII timeplot.

It takes fairly sketchy data to have this occur.  But such an example is the data for
permanent station SGLG for 2017 Aug 6.  You can get the SGLG observation data and
navigation messages as Hatanaka-compressed RINEX and RINEX, respectively, at (both
UNIX compressed):

ftp://data-out.unavco.org/pub/rinex/obs/2017/218/sglg2180.17d.Z
ftp://data-out.unavco.org/pub/rinex/nav/2017/218/sglg2180.17n.Z

The current qc is at:
ftp://data-out.unavco.org/pub/rinex/qc/2017/218/sglg2180.17S

The previous teqc versions gave something like this for the ASCII timeplot and PP:

  SV+------|---------|---------|---------|--------|---------|---------|------+ SV
   2|                                                __-------ccccccooIII---+|  2
  13|-__                                  __---------------__         __-----| 13
  16|---___           _-------ccc-------_                                  ^^| 16
  18|------------ooI^_                                                  _----| 18
  20|----__                                    __               __---cIII--II| 20
  21|------------_                                                  _^-------| 21
  29|---_                                                    __--cccccIII---I| 29
  32|------------ooooooooo+^_                                                | 32
   8|-_----------oo++_         __----cccooooooo-__                           |  8
  24|----------__                                 _-----------cccccc^^_      | 24
  14|-_----------ccccccccccoo+^_                                             | 14
  11|-      _----ccccooooo^^__        __--------------_                      | 11
  22|-       __--cccccccccccccccccc-^_                                       | 22
   3|            __--cccccccccooooo--o+_               ______                |  3
  23|              __^cccccoooooooo--ooI-----_                               | 23
   9|                   ___-ccccccc--cccooooooo+                             |  9
   6|                      ___^^^^__              __----------oooooo++_      |  6
  30|                           _^-----cooooooo------2----_                  | 30
  28|                              _---coooooooI-----2-------^_              | 28
  17|                                    __-------------------c^^_           | 17
  19|                                       __----------------ooooo+^_       | 19
-dn| ----  ----   + +  11++ +++++1113 112222231--- - -------+ +    ++   -- +|-dn
+dn|------------   1  1111111 ++23--3322223434---------------  1 111 -------|+dn
+10|878766667777666566777766655567777766667878866678878887665555566544456666|+10
Pos|            ooo oooooooooOoo     o            ^ ^       ^             ^^|Pos
Clk|^^^^^^^^^^^^                  ^^          ^^^^^^^^^^^^^^^        ^^^^^^^|Clk
    +------|---------|---------|---------|--------|---------|---------|------+
00:51:30.000                                                        23:00:45.000
2017 Aug  6                                                          2017 Aug  6
...
   antenna WGS 84 (xyz)  : -2262461.6097 -4016669.8575 2639144.8022 (m)
   antenna WGS 84 (geo)  : N  29 deg 59' 23.19"  W 119 deg 23' 28.21"
   antenna WGS 84 (geo)  :   29.989776 deg   240.608831 deg (= -119.391169 deg)
           WGS 84 height : -1060822.6661 m

Obviously, the mean PP from this earlier version of teqc yields a nonsensical
ellipsoid height.

With the latest teqc version which excludes solutions with the unrealistic elevations
(and note the 'K' symbols for certain epochs where the height was unrealistic):

  SV+------|---------|---------|---------|--------|---------|---------|------+ SV
   2|                                                __-------ccccccooIII  KK|  2
  13|K__                                  __----   K K-----__         ___   K| 13
  16|K--___           _-------ccc-------_                                  KK| 16
  18|K-----------oo+^_                                                  _  KK| 18
  20|K---__                                                     __---cIII  KK| 20
  21|K-----------_                                                  _^---  KK| 21
  29|K--_                                                    __--cccccIII  KK| 29
  32|------------ooooooooo+^_                                                | 32
   8|-_----------oo++_         __----cccooooooo-                             |  8
  24|----------__                                    ---------cccccc^^_      | 24
  14|-_----------ccccccccccoo+^_                                             | 14
  11|       _----ccccooooo^^__        __--------   K K_                      | 11
  22|        __--cccccccccccccccccc-^_                                       | 22
   3|            __--cccccccccooooo--o+_               ______                |  3
  23|              __^cccccoooooooo--ooI-----_                               | 23
   9|                   ___-ccccccc--cccooooooo+                             |  9
   6|                      ___^^^^__                 K--------oooooo++_      |  6
  30|                           _^-----coooooooo   K K----_                  | 30
  28|                              _---coooooooI   K K-------?_              | 28
  17|                                    __-----   K K--------c^^_           | 17
  19|                                       __--   K K--------ooooo+^_       | 19
-dn|-----6 ----   + +  11++ +++++1113 112222231-------------  +    ++   ----|-dn
+dn|------------   1  1111111 ++23--3322223434---------------  1 111 -------|+dn
+10|8787666677776665667777666555677777666678788     77888766555556654444    |+10
Pos|K    oo    oooooooooooooooooo    o            K K       o             KK|Pos
Clk|^^^^^^^^^^^^                  ^^          ^^^^^^^^^^^^^^^        ^^^^^^^|Clk
    +------|---------|---------|---------|--------|---------|---------|------+
00:51:30.000                                                        23:00:45.000
2017 Aug  6                                                          2017 Aug  6
...
   antenna WGS 84 (xyz)  : -2333422.1562 -4842783.8222 3421322.9442 (m)
   antenna WGS 84 (geo)  : N  32 deg 38' 57.48"  W 115 deg 43' 35.00"
   antenna WGS 84 (geo)  :   32.649300 deg   244.273611 deg (= -115.726389 deg)
           WGS 84 height : 87.8745 m

Teqc's PP is now pretty darn close to SGLS's real coordinates:
lat = 32.649266  lon = -115.726379  h = 78.4 (meters)
... even with this quite messed up data.

Happy teqc-ing!

cheers,
--lou

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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

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