Leica GS15 Version 2 Questions

Interesting question! We have 9 GS15 receivers that we use for static observations, and they are a mix of "R1" and "R2" with serial numbers below or above 1508600. I spent considerable time trying to get to the bottom of this a few years ago, and my conclusion in the end was that they are essentially equal, and we treat them as equal now. Some of my findings:

• When the GS15 antennas were first sold to consumers, I believe 2009, they did not support GLONASS yet but were marketed as being capable of that. Shortly later, either 2010 or 2011 they were sold with that capability, and I believe that this is where the "break" happened and for some strange reason it was "assumed" that different hardware was involved, or there was confusion about hardware vs firmware capabilities? I'm speculating here, but that's the impression I'm under.
• Dealers have confirmed there are no differences in part numbers for repairing any GS15 regardless of serial number.
• There are separate antenna calibration files for "R1" and "R2" versions of the antenna. Again, I think the version is purely made up due to some unknown reason. Calibration files can vary depending on where in the world they are created, and the "R1" contains values only for GPS while "R2" contains values for GPS and GLONASS.

I'm guessing here, but to me it looks like someone had the antenna sent in for calibration after GLONASS was enabled in the firmware, and the antenna calibration folks created a new version of the antenna called "R2" to differentiate it from the original calibration. Annoyingly the "R2" calibration does not exist in some software packages and can't be added as a custom antenna, only the first one (without GLONASS) is supported. The impact of switching between the two different antenna calibrations on actual post processed baselines is essentially zero based on our testing.

If it's important to you, then I would suggest you complete your own testing and I'd be curious to hear of your conclusions on the subject.