[OSM-talk] Affordable 1 CM high precision GPS.

[Greg Troxel]

Hartmut Holzgraefe <hartmut at php.net> writes:

> On 5/5/24 21:40, Greg Troxel wrote:
>>   but it (15cm georeferenced aerial images) does not work in tree cover
>
> not having watched the video either, and having just a very basic
> understanding of RTK, but wouldn't that basically be affected by
> reflections from trees the same way as regular GPS, and so be less
> precise when being in a forest?

theory:

The signals are weaker and probably there is more multipath.  The issue
is getting a "fixed solution", resolving the integer ambiguities of
phase.  This low enough noise in the solution so that the chosen
solution can be judged better enough than the others.

reality:

I find that with open sky, I get "RTK FIX" reliably.   In the forest, I
get "RTK FLOAT", meaning differential, but without resolving the integer
ambiguitites.   People seem to think that more expensive stuff does
better in forests, as in $20,000 Trimble rather than F9P.   I'm not
saying they are wrong, but that's not too relevant....