Some good reading...

The AIM chapter on GPS:

http://www.faa.gov/ATPUBS/AIM/Chap1/aim0101.html#1-1-19

AOPA ASF article:

http://www.aopa.org/asf/publications/sa01.pdf

A suicide switch story

http://www.avweb.com/news/system/184452-1.html

Peter Dana’s article on how GPS works:

http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html

Trimble’s GPS explanation:

http://www.trimble.com/gps

Ebook on GPS navigation:

http://www.cockpitgps.com

This talk!

http://williams.best.vwh.net/smxgigpdf/smx2004.pdf