Global Positioning System (GPS) and miscellaneous articles.

Selective Availability turned off May 1st, 2000!

Basic Description of the GPS System  Where some of your tax dollars went.

Setting up your GPS receiver for UTM grid  UTM is best, find out why.

USGS Fact Sheet on the UTM Grid (pdf, 153K)  Requires Adobe Acrobat Reader.

USGS data on NAD83 to NAD27 offsets (pdf, 99K).

About Survey Monuments and Benchmarks