The Center for Spatial Analysis and Mapping (CSAM) is geography's GIS and GPS lab. Geography's GPS facilities include Trimble Navigation Ltd's GeoExplorer GPS receiver.

Figure 1. The GeoExplorer GPS receiver and battery pack.

The GeoExplorer stores positions in files. About 11,000 positions can be recorded in up to 99 files. At a typical position logging rate of 1 position per second, this will allow about 3 hours of mapping. The 12V camcorder battery that powers the receiver provides about 7 hours of continuous operation and can be fully recharged overnight. The raw data stored in the receiver can be downloaded to a PC in CSAM. Trimble Navigation Ltd's Pathfinder Office software is used to process the raw data - for example, to group and average positional data, to improve positional accuracy, to view positions onscreen, and to export GPS data to a GIS. CSAM has 4 GIS software packages that can import GPS data - ArcInfo, ArcView, AtlasGIS and MapInfo.