So I have been doing some testing to determine how far from the base I can travel whilst getting corrections from an Emlid RS2, Trimble TDL450H external radio and into my RS3.
On the first test, I drove until the RS3 lost corrections and then turned around and came back to the base checking along the way, and it would not receive corrections again at all. I had to restart the receiver, and then all good.
On subsequent tests, I drove until I no longer received corrections for approx 1 minute and then turned and came back, and the same thing happened, no corrections, although these times I was able to turn UHF correction input off and then UHF corrections back on, then all good. One time fixing again within seconds, and the second time not until I was within 100m of the base.
Has anyone else been having similar issues or able to offer suggestions?
On a side note, the range experienced was rather disappointing. I had the base antenna 4 metres in the air and the radio running at 25 watts, and on the same test area at the same time of day, and with the antenna 1.5m lower, I have been able to achieve the same distances using Lora!
It was only lightly treed. Definitely wasn’t via LoRa. Setup was as follows:-
Emlid RS2 as Base with all constellations and following RTCM messages 1074 @ 1Hz, 1084 @ 0.5Hz, 1094 @0.5Hz, 1124 @ 0.5Hz and 1230 @ 0.1 Hz. GNSS settings update rate of 5Hz.
Trimble TDL450H connected to RS2 using 9 pin lemo to 9 pin DB9 male into Trimbles programming cable.
RS3 essentially identical to the RS2 bases details.
Working close by there was no issue, but as soon as I started losing fix for an extended period was when the oddities started occurring, another one being that when it did obtain fix again after turning correction input off and then back on, it would no longer show the baseline.
Thanks. Aha, funny you should mention the antenna, I did some trials with a cheap brand 5.5 dbi first, then with a 0 dbi Trimble shorty, and found the Trimble shorty did better than the long higher gain one!
I will try as you suggest with just the GPS and GLONASS cons, although it would be nice to have at least a third cons in there. Still I wouldn’t have thought the number of cons used would stop the receiver getting a fix again when it came within range of the base. It’s as though the receiver isn’t even looking for it until i turn corrections off and back on again.
Different radios work similarly regarding the requirement of a clear line of sight between the base and the rover. Also, the obtained baseline and the correction stream may depend on several factors, such as the radio’s output power and all the environmental conditions.
However, I believe that a baseline of 2 km is quite common for setups using radios.
Thankyou for your repose. Do you have any thoughts as to why the RS3 doesn’t receive corrections again automatically when getting back in radio range of the base? It’s as though it doesn’t even attempt look for corrections until I turn correction input off and then back on
Just checking as the LoRa antenna can also be used as a uhf antenna if you don’t have the extra antenna, at the compromise of range, which I thought might be your issue, just double checking not insulting
I’m aware however users have been told they can use it so again, just double checking. When we got the RS3 to test the UHF antenna wasn’t even available
Doesn’t sound like just checking, you’ve said users have been told but it’s you that just made the statement purporting to be fact that it can be used.
I would leave it alone, the UHF antenna is available for a reason. Not a good look questioning an obviously knowledgeable user at the same time encouraging other users down the very same wild goose chase.
I’d like to leave an update here. We’ve investigated the issue with the correction stream via UHF, and our team has found its root based on Brenton’s dataset. We’ve started working on it, and if there’s any update, I’ll share it.
Also, I’d like to add that setups with LoRa and UHF radio are different, but both require a clear line of sight between the base and the rover. As previously mentioned, the possible baseline depends on multiple things, so each survey should be considered uniquely.
