The ProMark 500 (PM500) receiver got a major firmware upgrade a couple of weeks ago (firmware S529GI23) which among other enhancements tuned Time-to-First-Fix down to 5 to 10 seconds and results in much better dynamic performance.
This upgrade also opened the door to a new PM500 hardware revision with a new antenna (ASH802129) and support for Galileo and L5. It appears that there will be no change in PM500 head pricing. The part number for the updated head is 990596A.
Ashtech has always claimed that they will support new technology when it makes sense, and I suppose Galileo may have as many as two preliminary SV’s in orbit in 2011. If Galileo pans out, then the new PM500 will be ready.
I also suspect that the new antenna shares technology with the 661 antenna used with the PM200. The PM200 antenna is a super high gain, highly tuned element that is responsible for some of the PM200’s quick time to first fix.
The new antenna NGS calibration is avalable here http://www.ngs.noaa.gov/cgi-bin/query_cal_antennas.prl?Model=ASH&Antenna=ASH802129%20%20%20%20%20%20%20NONE Of note, the original PM500 receivers were calibrated with the UHF radio antenna facing north, while the new revision is calibrated with the OLED panel facing north.