Working in Glen Allen, VA today Trimble planning software tells me I should see right now: 8 GPS, 8 GLONASS, 7 Galileo, 10 Beidou.?ÿ I do see all of those on my skyplot.?ÿ The R10 base is in a wide open field, and so is my rover.?ÿ I'm using between 22-25 satellites in the constellation.?ÿ Due to lower noise and stronger signal Galileo is preferred over Beidou if two SVs are very near each other in the sky.?ÿ I looked at that GNSS-Radar site and I don't trust it.?ÿ It is giving different satellite numbers than Trimble GNSS planning.?ÿ I think it's ephemeris is out of date.
@plumb-bill number of satellites is not your controlling or most important factor when using GNSS, PDOP is. And there are many Beidou satellites, some of which are not of much use by surveyors, only their newer ones. Use the PDOP graph to find your bad times of the day, not satellite count. You can have 20+ satellites but not great PDOP because you could have 2 or 3 clusters of satellites where there's 3 satellites taking up geometrically the same space.
I get plenty of Beidou SV's all day in western PA. And they are in all four quadrants. Tracks are similar to other constellations
Yeah...like our future Chinese overlords are going to invest in a GNSS system that's not efficient at targeting US sites with cruise missiles.?ÿ ?ÿ
I think that depends on your goals. I remember getting acceptable PDOP with 5 Navstar satellites, but I couldn't get anywhere near ONE tree - let alone the woodline. Also, when I'm standing in a dense forest I can watch a couple Galileo SVs ascend and my RMS goes down almost in lockstep. So how many of what quality seems to matter more than anything in my experience. PDOP is one way of expressing that, but with modern receivers that can rigorously cycle through turning signals on and off to weed out multipath MORE SVs means MORE ability to adapt and overcome.
