This TatukGIS Internet Server sample demonstrates the simulated GPS tracking of an automobile on a vector street map and the snapping feature to adjust for the GPS position errors by snapping the presentation of the tracking points to fit the road.

The vector map layer for this sample is a segment of standard TIGER road/street map data. The TatukGIS Editor was used to clip this map segment covering a portion of north-eastern Virginia and a portion of the neighboring District of Columbia and to convert the data from the TIGER file format to a SHP file. The TatukGIS Internet Server product was used to project the map layers to the northern Virginia state plane coordinate system, which is based on the Lambert projection. Post processed GPS tracking points, are held as x,y coordinates in a database file in the WGS84 coordinate system (like is generated by most GPS devices). The Internet Server reprojects the tracking points, on-the-fly, from WGS84 to the northern Virginia state plane coordinate system for presentation on the map.

Check the “Focus Car” option to automatically zoom in and scroll the map view to follow the car. Check the “Snap Route” option to activate the snap-to-road feature. The map view is set to refresh every three seconds.

The ASP.NET source code for this sample may be reviewed by clicking on this link.