This is probably old hat to many gps users. I was out this morning on a job to do some RTK and rapid static on some recently timbered land. i had the base out in an open field 1000 feet away. There were no obstacles within 200 feet of the base. i couldn't even get the rover to lock in the open field. Sometimes there were 16 sats showing and a PDOP of 1.7
I proceeded into the cut-over and managed to get just a couple locks all morning. Yesterday on the same site with the same base station I was locking even as I walked through the cutover.
Was there anything I could have done to help the situation? What would have tipped me off that this might happen? What gets me is that I got no lock even out in the open field 100 feet from the base. Radio communication was OK.
I'm using Topcon Hiper Lite+.
Thanks
Voice trumps data. Did you try switching radio frequencies? It happens often enough to me to be a PIA, but gotta do what ya gotta do.
No. I've never done that before. I use SurvCE 1.67 with an Allegro DC.
Are frequencies of the Hipers switchable in the field?
Yes, with Modem-TPS. (and a laptop)
I can change the frequencies on our HiperLites with the DC (TDS)..just depends on whether you've got a new enough version.
Thanks. I'll have to check that out. There was a lot of logging machinery and a dozen pickups across the street. Feller-bunchers, chippers, trees were going from standing to chips faster than you could count them.
When it does that, look at a sky plot of the sats. They may be bunched up and have "bad geometry" as trimble used to say.
If it makes you feel any better, I had a similar problem yesturday around noon. I was almost within sight of my base, and I would go from fixed to atm. over and over and over again. I have an older Hiper with legagy base and pac crest 35w radio though. This used to happen all of the time, and I finally sent it in and the tech worked on it for litterly days, said he never really could figure it out, but it worked when it came back. I was really bumed when it started it again, but then it starting fixing quick again, and worked for the rest of the day no problem. I had 9-10 GPS sats in decent areas. I never could figure it out, and I hope it doesn't start happening all the time again. It is a GPS problem, I think it is a radio problem, as when you bring up the screen it shows the radio og from 1 sec latency (normal) and starts counting 1,2,3,4, then no radio, and every now and then it get a sniff of signal again.
I did not think to change radio freqs and it start working again.
If anyone has some ideas, I am open to suggestions.
Try turning off GLONAS. I've seen a bad Russian sat and it won't let you get a fix. If you really need the GLONAS and turning it off fixes it, you can turn one off at a time until you find the bad one.
Would love to be able to turn off GLONASS 🙂 , alas got my Hiper the year before the GLONASS boards came out. Strictly GPS here.
I have the question in the back of my mind about the radio becoming too hot. I kinda forgot that I had this problem a few weeks ago, sunny and about 90d, no wind. But when it happened a couple of days ago it was partly sunny, 70d and 20mph winds, which would have kept it cooler. When I had teh problem a few years ago, the weather didn't matter, 30d-60d.
one time I was doing RTK with my co-worker (another LS) and suddenly the radio stopped transmitting. I tried all of the usual stuff at the rover, no fix. So I rode the ATV back to the base. He had left the Trimmark IIE radio closed up inside it's carrying box on a hot day. As soon as I got it out in the air and the cooling fans had 5 minutes to cool it off it started transmitting again.
We have also had problems
Both all day yesterday and this morning - this afternoon is better though.
We have also had problems
DITTO
What Liz said.
Change radio freq.
Check voltage, base, and rover. Check antenae connections base and rover.
Clean and reconnect them.
Check continuity on base antennae, wire.
Look at sat geometry.
One sat may be giving bad data, and nothing will fix.
Move 15' away, and see if you were getting multipath, off an unseen item. road sign, or old rusted barn roof.
There are many things, and you will eventually learn alot of them.
N