GPS was pretty much paid for in the 1980s out of the DoD's budget to the tune of 10 to 15 billion $US. The birds with those atomic clocks were launched just after the 1983 realization/model of the earth was calculated, viz. NAD(North American Datum)1983. And much new data was collected quickly for yet another realization, WSR84. Any rate, color just burns power and check for the Waas capablitity(give ellipses of error near 10 meters) which is land based correction from each coast on the North American continent. Works great when they are broadcasting accurate corrections. Have a look at the Rino com. devices also. I think Cabela's has them.
Kind Regards,
Raimey
rse
Last edited by ellenbr; 12/30/08 11:38 PM.
