Does GPS get screwy in a light falling snow?
For rtk/dgps work ?
> Does GPS get screwy in a light falling snow? should work ok, from what i have done and been told
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> For rtk/dgps work ?we don't use rtk, sorry
never had any problem with it here don.
It will be affected if the base gets covered with snow.
I have used RTK a few times in both light and heavy snow conditions, and I don't recall ever seeing any degradation in the results.
A "significant" buildup of snow on the base station radome can (I hear) have an impact on both signal strenght and accuracy though. I have been using a Novatel 503 w/spike radome (see link below) for the last few years on my base station, so I don't worry much about that anymore.
http://webone.novatel.ca/assets/Documents/Manuals/om-20000018.pdf
Loyal
This is an old L1/L2 base antenna. Yesterday morning it probably wouldn't have worked since we got 3 inches of wet icy snow overnite. The sun took care of that by noon, but it is a problem this time of year.
Why wouldn't it have worked?
The only problem that I can see related to snow and Network RTK MAY be the length of the lines. If your are using NTRIP or other means to get really long range fixes then you could exceed your budget for tropospheric delays IF the base is in clear weather but you are in the snowy stuff. This is not likely, so as long as both have the same conditions then I've use GPS, both static and NTRIP, in falling snow conditions without any noticeable degradation in positional accuracy.
It doesn't happen often; but when that antenna gets covered in snow thick enough it won't see satellites or it picks up just a few. When you start the base unit you will see that (usually I sit there thinking what's wrong with the cable before it hits me-the snow duh!) and I can't think of a time when it caused too much of a problem; you just get up there and clean it off. In the field I've never had it happen. I always wondered if the base unit generates just enough heat to keep it clean.
The one on the garage just sits up there all night long wihtout being powered up or in a warm office so any snow that falls at night will stick.
I wouldn't have thought it would make much difference, but I've had some problem with my Promark 3s in snow. They seemed to lose signal once there was some buildup. As I recall, it wasn't much buildup before I had problems, maybe 1/4" or so. But they were set up in a location of limited sky visibility as well, so the two factors together likely caused the problem.
There have been a number of papers published over the years concerning (or at least discussing) this issue.
Google: 'GPS snow degradation radome'
An easy one to get at is:
ftp://igscb.jpl.nasa.gov/pub/resource/pubs/04_rtberne/cdrom/Session1/1_3P_Poutanan.pdf
FWIW
Loyal
My understanding is that snow is a pretty good source of multipath, but it hasn't been a regular support call that I receive.
That is what my concern was, multi-path.....
But now I'm done with the beachfront job and I'll let you know how it comes out....
I have done a lot of static work in the winter, and have never had a problem, even with several inches on the antenna. Never had buildup that I can recall doing RTK... Must have been moving too fast 😉 actually, if it is going to snow, there is probably some paperwork that needs to be done.
