For point surveying, I’m mostly using static post-processing with 2-7 km baseline & a few minutes observation time. I don’t have SBAS available and use GPS & GLONASS. I was wondering if someone could help me about some specific settings.
My settings are mostly based on experience, the docs here, and rtklibexploer (see here for some nice explanation of the options).
1) combined vs forward:
combined should get us more fixes, but could also increase false fixes… I tend to keep it combined.
2) fix & hold vs contunious:
same again: fix-and-hold should keep fix more stable, but might also stick to false fixes longer… And if we use fix-and-hold, what AR filter would you recommend? (rtklibexplorer sets Max Pos Var to 0.2 for m8t, while the emlid postprocessing guide sets it to 0.99 for kinematic)
3) elevation SNR mask?
any strong opinions on this? I mostly use 20 degrees elevation mask. Hope to avoid soem of the multipath…
4) using prcise clock and ephemeris data, IONOX data, earth tides…
From what I understand about the theory, all this should have very little influence at the relative short baseline I’m working on. I see generally little improvement using them. Also, as far as i know, the standard clock/eph data from IGS only covers GPS?
Does it make much sens to use them without atx information?
Does anyone have good results using any of these, especially also for longer baselines? Which settings should be considered here.
5) filtering out sats with cycle slips
I have not achieved better results with this
6) Reject threshold of GDOP/innov:
rtklibexplorer recommends a high setting (1000m). Not sure if this is needed in static mode?
7) data collection rate
I remember @Luke_Wijnberg said somewhere it matters not so much for static pp, the observation length is more important. So I now usually use 1Hz.
8) min ratio to fix ambiguity
I tend to go a bit bellow the standard of 3. Again a trade off with false fixes…
and one question on results:
I recently get quite some float only solutions with low spread, often around 5-7 cm, using 15 min observation.
Am I right that as it is float, this might likely anyway be off by decimeters?
Looking forward to hear your opinions!