RX issues with accuracy

I’ve bought 2 of the RX units and talked a guy I know into buying 2 as well. Neither of us are impressed. They do not do as well as the RS2 or RS2+ units. Using the same correction service, with the same pole in the same place, just changing out the GPS receivers, I regularly can get 1-2cm precision with the RS2 but closer to 30cm with the RX units. I did this same test several times over the course of several weeks and only once did the RX match the RS2 in accuracy. It was on the day with the most pristine weather imaginable. Any other time, not so much.

The RX does seem to do okay with a base/rover setup with a short baseline. I suspect the RX is similar to the RS+ units, in that it can technically get 1cm but you shouldn’t hold your breath waiting. I can find a use for the RX’s I already own, but I won’t be buying any more.

@rpc78 - Hi Ryan, thank you for posting the results of your tests. One thing I wondered about is related to what Michael was mentioning. I understand that your tests involved the same correction service, and just want to make sure I understand (what I’ve only assumed) that all of your tests used the same Android cell phone, had the same GSM/ LTE generation; e.g., 4G, the same number of bars, the Emlid Flow app, and we’re only talking RTK and no post-processing. Please affirm which of my assumptions are correct and which are not.

The number of bars displayed in the upper ribbon of your Android device is a simplified indicator. A better way of gauging cellular network signal strength and speed is using Opensignal. Opensignal is a free to use, advert free mobile connectivity and network signal speed test app.

For example, just sitting here in the office my Galaxy S23 is showing 5G with 4 bars. Opensignal shows a latency of 51 ms and a download speed of 151 MBps. If you try these tests using Opensignal, be sure to turn off your phone’s WiFi.

Another thing to be aware of is switching towers. Tower switching is transparent to the user and is continually being done as signal strength from the tower to your device dips, and the network switches to another tower with better signal strength.

For example, again, just sitting here in the office with my Galaxy S23, 5G with 4 bars. Opensignal shows a latency of 46 ms and a download speed of 162 MBps.

The really nerd-cool thing in Opensignal is the map of cell towers. In test-1 above, the map showed that the device was connected to a tower-1, and in test-2 connected to a different tower.

Years ago, we used to have to do mission planning in order to make sure we’d be seeing enough SVs. Now we need apps like Opensignal when doing Network RTK.


Wow, that’s a cool website and app !

Thanks for the suggestion !