** Note - these links are provided as a service and no attempt has been made to verify accuracy or content of the linked sites.

• Realtime Tracking of Satellites and Space Station
• Peter Dana (U. of Texas at Austin, Dept. of Geography)
        An Overview of GPS
        Map Projection Overview
        Geodetic Datum Overview
  
• NOAA: Determining Heights with GPS
• UTM zones for US lower 48
• UTM zones for Alaska
• UTM zones for Hawaii
• David Wilson's GPS Accuracy page
• Sam Wormley's GPS Error page: Great cheatsheet on how to estimate your GPS Accuracy
• NOVA Online - GPS: The New Navigation
• MicroSoft's Terraserver - DOQQ and DRG images for use with ArcPAD and TerraSync