Tom N - 8/17/2008 18:58 Hi Don Were you referring to the twenty-mile plus radius with this statement? “The accuracy of the CORS station will beat an on farm base hands down.” I maybe wording that statement poorly. What I am trying to say is that the absolute position of a CORS base is much more reliable than an on farm base. If a CORS station moves, it is removed from the "reliable list". Most on farm bases are mounted in location of convenience. I keep hearing of many being on top of elevator legs. Others are on top of a shop building that moves with the wind. I won't even to into the problems of a mobile base if you want repeatability.
[QOUTE]We may be splitting hairs here but it’s hard for me to see how the CORS signal could beat hands down the signal from the single base if your within 6 to 8 miles of that base. It has now been proven to my satisfaction that high quality receivers are easily capable of 2" accuracy at 20 miles from the base. The problem in the past has been getting the signal out to the twenty mile range. Radios would not do it. As we have discussed before the key to making this CORS or DOT VRS RTK signal work will be in the reliability of the cell signal. How do you suggest someone go about testing for 100% cell coverage on all the ground they farm? If you get a good signal today is it safe to say that you will get the same result on the other 364 days of the year? How do you correct for spotty cell signal? I have always maintained that good cell coverage is the key. I have been to your area and I know that radios work much better there than they do here. I would ask you the same questions about your radio coverage. How do you test for or guarantee 100% coverage on your radio system? Why you do need repeaters? I have run in a 65 acre field with the base station setup on a tripod at the edge of the field. I went behind a tree 500 yards from the base and lost signal. Sorry for so may questions but I’m coming at you as a service provider. Would I be responsible for poor cell coverage or a glitch in the DOT service? With a local base or RTK network, full control is in the hands of the owner except for the Gov providing the GPS signal. Tom N. Tom, I highly respect your opinions and I know you have the best interest of your customers in mind. But the CORS network is an RTK network just like the one that you operate. The main difference is the method of transmitting that signal. Currently there is no one "best transmission method" that works in every location. But in my experience cell phone transmission works 100 times better than 900 mhz radio ON MY FARM. | 
Questions about Coors & cell phone differential service
