RTCM subscription services

GPS/GNSS Development Boards
1

I just got my RTK Express today. I intend to use it for construction-related work, and will need the RTK accuracy. I think I might prefer to use a RTCM subscription service than a base-rover configuration (though I’m not entirely sure, and am new to all this), but I can’t quite figure out how I do that: do I need the telemetry radios? Can I do it over bluetooth or wifi? I may have not understood what I was looking at, but I don’t seem to have found any info on use of subscription services.

I think that would involve NTRIP, right?

Thanks for any help or pointers.

I didn’t get a ground plane, and

2

This is a good starting spot: https://learn.sparkfun.com/tutorials/wh … ps-rtk/all

If you will be working in an area that has cellular reception, skylark seems to be the easiest at the moment: https://www.swiftnav.com/skylark

3

Thanks, I’d read that but it was a helpful refresher.

I’m expecting to use the RTK Express with a custom app that will be polling position data directly. I’m assuming I can do that with the Bluetooth on the RTK Express already. Can I not use that same connection for RTCM? They suggest using a “Bluetooth Mate Silver” which is a device to send serial data across Bluetooth. For that matter, the RTK Express has wifi too, so (if I have onsite-wifi, or use my phone as a hot-spot?) perhaps that could work too: am I missing something? Perhaps I’m underestimating the demands of RTCM…

Thanks for your help though! I think I might try UNAVCO for free RTCM while I get things set up, though there isn’t a station close enough to use in the long run. I figure I can work out the configuration and operation before I sign up for a paid subscription. It’s sort of weird how few UNAVCO bases there are in the mid-Atlantic.

4

I’m assuming I can do that with the Bluetooth on the RTK Express already. Can I not use that same connection for RTCM?

Yes and yes. The Bluetooth SPP connection between the RTK unit and your phone is just serial pipe: NMEA comes from the RTK unit and the phone can push RTCM back to it. Having an NTRIP Client built into the app is common. You can try it with SW Maps right now: https://docs.sparkfun.com/SparkFun_RTK_ … e/#sw-maps

5

Excellent, thank you. I think I needed to borrow some confidence! I’ll play with sw-maps.

6

I read the SW Maps guide posted above (https://docs.sparkfun.com/SparkFun_RTK_ … _software/) If I want to build a NTRIP client into my own app (say andriod app), Is there any place I can find programming API/examples? Also how do I have the phone app connects with the RTK Express if RTK Express is not connected to the internet, where can I find NTRIP setting such as address, port and user credentials assuming my phone is paired with RTK Express via Bluetooth already?