I did some testing today with a simpleRTK2b (F9P) in my truck (antenna on roof) with a Digi SX in the XBee socket (arduSimple LR radio) and ntrip via u-center for redundant correction rtcm3 streams. Both were streaming from the same base station.
The F9P seems to handle receiving duplicate rtcm packets just fine. Looking at the UBX-RXM-RTCM message, the F9P marks the all the rtcm packets (including the duplicates) as having used them in its solution (except for the beidou packet because my F9P doesn’t need it). I haven’t used it for steering yet but the deviation chart showed a nice stable position with one or the other or both streams active. Maybe if the F9P was close to it’s max cpu usage adding duplicate rtcm would hurt but otherwise I think it will work well to use a second stream as a backup.
This is handy to know, if you had towers two distant farm sites in an area, even with hills you would get a strong connection off one or the other.
You could run the base to Ntrip, then any house with a internet connection and a data radio could be a redundant repeater tower.
You’re thinking of having your RTK correction radio hop between towers? That would still only be one rtcm stream into to the F9P unless you mean to use two different radio setups. What I did was input rtcm via the XBee socket (uart2) and usb at the same time (900 MHz radio and cellular ntrip).
Yes I understand you did it for a fallback stream, so if one failed the other one is still sending up to date corrections.
Since the Rover can receive on two different inputs from the same stream of corrections.
So with this you can get easily rid of dead spot, or make the stream almost uninterruptible.