I have seen some advertised.DTV accessories /google etc. but for a moving vehicle...$$$!
I await info with you. Analog will work but you move from zone to zone so you gotta park...and you are back where you started.
Contact an RV dealer there are a couple brands available and the RV configuration is different from RV model to RV model. They may cost more initially but due to leaks and damages may be cheaper in the long run.
Some of the RV dealers are also representing the new DirectGo system. Ask DTV. Bring bucks.........still ,the tracking on the go........??? DVR while parked. Like to see what shows up.
Tracking on the go works well.. If ya got the money to buy the system.. Only problem is when ya drive you have to ride on roads that don't have a lot of tree cover.. But it does work.. It just takes a fat wallet.