Systematic Residual Charts 2021-2022 (Guadalajara Workshop spoiler)

[Toshimichi Otsubo]

Dear SLR Station colleagues,

After a few years' break, a number of "station x satellite" systematic residual charts are created using one year data from July 2021 to June 2022.  See you at my poster in Guadalajara or online (https://congreso-yebes.ign.es/web/portal/home).

What's new in 2022: ITRF2020 velocity and PSD.  Rodriguez's CoM corrections.  GOCO6S gravity model.  LAGEOS-1 and -2 handled separately.

• POD residuals vs Intensity (returns per NP bin)
  http://geo.science.hit-u.ac.jp/slr/bias/2022sp/SortIntensity22b.pdf
  (Negative trend indicates a typical "stronger=shorter" dependence.  Probably underestimated for LAGEOS because it also depends on elevation.  Some stations moved to single photon mode and eliminated the trend.)
• POD residuals vs Single shot RMS
  http://geo.science.hit-u.ac.jp/slr/bias/2022sp/SortRms22b.pdf
  (Positive trend indicates the mean being affected by the tail clipping.  I know it's a bit controversial - I am not sure whether it is harmful to geodetic products or not.)
• POD residuals vs Applied system delay
  http://geo.science.hit-u.ac.jp/slr/bias/2022sp/SortDelay22b.pdf
  (Negative 1:1 trend indicates untrue variation in calibration.  Some stations show very stable calibration: only 1 mm RMS thoughout the year in Wettzell 8834!)
• POD residuals vs Local time
  http://geo.science.hit-u.ac.jp/slr/bias/2022sp/SortHour22b.pdf
  (Day-night observability and stability.)
  
• POD residuals vs Range rate
  http://geo.science.hit-u.ac.jp/slr/bias/2022sp/SortRR22b.pdf
  (Negative = pass start, Zero = closest point, Positive = pass end.  A slope indicates time bias although such a case is not clearly observed this time.  Do not worry much with a small wobble if seen only in one satellite - possibly due to insufficient POD models.  Asymmetric "Counts" histograms show that some stations do not try to cover the whole pass.)

I am still making the poster and the link will be posted here later.  It is impossible to include all these charts in the poster, so please have a look in advance.

See you in Spain,
Toshi
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Toshimichi Otsubo (t.otsubo@r.hit-u.ac.jp)
Hitotsubashi University

[Toshimichi Otsubo]

The link to the poster (PDF; provisional): http://geo.science.hit-u.ac.jp/slr/bias/2022sp/20221107-poster-otsubo-systematic.pdf