I run a maximum of 30 miles from the CORS station. At that distance, I do not get sub inch accuracy. My opionion (and it is just that) is that you will need to be within 20 miles to have true RTK accuracy. At 30 miles, my pass to pass accuracy seems to be 2" or less, but the "real accuracy" (repeatability) can get up in the 3-4 inch range. I can stay on 30" rows, but I will be off some on 21" tramlines with 18" wide tracks at times.

As far was vegetation and the RTK signal, that all depends upon your carrier signal. I have a good cell signal and trees and vegetation do not seem to affect it. Where trees and vegetation hurt is with the GPS signal itself. You need a minimum of 5 satellites above 13­­° to maintain a RTK fix. There are time during the day with the number of satellites in view is low. During those times if a tree blocks too many satellites you will loss the GPS signal. That is a real problem here.

I think you will be fine at five miles. Your only problem will be trees and the GPS signal.