Data Collection and Acquisition

To develop an effective GIS, PWT performs data acquisition from sources as diverse as GPS surveys, databases, and paper maps.

To conduct GPS surveys, PWT GIS specialists collect a geographically referenced position and import/migrate the data into the GIS format to build a GIS or to enhance or validate existing source data. Field data acquisition can be done independently, or in conjunction with GPS data acquisition activities. PWT provides QA/QC ground control for our mapping and imaging projects to ensure the accuracy of point features to be converted to GIS.

Base mapping accuracy requirements dictate the conversion approach of hard copy maps into digital data. Scanning produces raster-image data when only image display functionality is required. To convert hard copy source information into accurate digital vector data, PWT conducts heads-up digitization of the raster image, or uses board digitizing or tracing paper source documents when necessary. When possible, automated or semi-automated vectorization processes are used to ensure conversion accuracy and efficiency.

Last updated: 6/26/2008