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Maquoketa, Iowa 52060 | Yes the Javad propaganda is a good layman’s explanation. Plain and simple you shouldn’t mix brands in precision applications when GLONASS, L2C, L5 or other constellations are involved unless you have a proven mechanism to remove all/most of the bias. I've been doing some extensive cross brand testing on the VRS Now, Iowa DOT, and DigiFarm network here in Iowa and Illinois. The DigiFarm network seems to be the only one to have it figured it all out, as they have GLONASS bias tuned mount points for each brand of equipment, which supposedly mitigates these issues as all their base stations are Trimble.
Here's a couple papers that was given when asked about this this issue:
http://acc.igs.org/biases/glonass-phase-biases_jog11.pdf shows Leica and Trimble being 4 cm different!
http://www.denshi.e.kaiyodai.ac.jp/jp/assets/files/pdf/content1/ion... this is really the best real world example of HOW BAD IT IS. Note that NovAtel is the same as Leica. Also note that supposedly Javad "knows" how to calibrate them, and obviously they failed miserably in this example.
None of these research papers even mention Deere, AutoFarm, or Hemisphere receivers, so nobody in the scientific community seems to know the magnitude of the effect on them probably because they are never used in the professional positioning markets and those manufactures have not gone to the expense to calibrate their systems. So mixing say a Deere rover receiver with a Leica base could cause who know what errors or line jumps. Unless you have some really smart people that really know what they are doing you just shouldn’t mix brands if you want high precision.
I have been told that even mixing antenna types messes with your accuracy. So, I think that may be the topic for anther thread. | |
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AgLeader RTK Base with Trimble Reciever
