Lambda Tech International - What is GPSVision?

What is GPSVision^TM?

New Generation of the GPSVision^TM System

GPSVision^TM is a mobile mapping system developed by Lambda Tech International, Fort Wayne, IN, USA. It uses the Navstar Global Positioning System (GPS) and Inertial Navigation System (INS) in combination with four high-speed digital stereo cameras. The integrated GPS/INS system provides the position and direction of the GPSVision^TM system, and the synchronized camera pairs take images of the road environment while traveling at normal driving speeds. Every visible object on the stereo images can be measured and precisely located in the global coordinate system. Utilizing Lambda Tech's advanced integration system, GPSVision^TM provides georeferenced digital images and the transportation infrastructures of the road or railway environment. All data is accessible to the end user, engineer or digitizer at a standard Windows personal computer utilizing the unique Feature Extraction Software developed by Lambda Tech.

How does the GPSVision^TM system work?

The principle is simple. Drive at posted speeds on roads and 35 mph on railroads and collect digital pictures that yield positional data accurate enough to make GIS quality base maps. The execution is also simple. Mount the system on a van or high rail vehicle and drive. Stereo digital pictures, GPS and inertial data are collected and written to the GPSVision data record. After differentially correcting and processing the GPS data, the data are stored on CDs or other media. Images are spaced at 16 meter intervals for highways or railways. User defined spacing of 10 to 12 meters can be used for streets in residential or urban areas.

Map and GIS data base creation is easy. Just point and click the mouse at any visible object, i.e. pole, sign, fire hydrant, manhole, guard rail, bridge column, in front of the cameras to a maximum distance of 40 meters. An asset symbol is placed on the map and its location on the surface of the earth is logged with a horizontal accuracy of one meter or less. Following edges of pavement or rails, adding attributes, measuring distances between features, outlining areas or determining clearances to within a 10 cm relative accuracy in the same picture is as easy as pointing and clicking again.

At the heart of the GPSVision system is the positioning module consisting of geodetic quality GPS receivers, inertial guidance and a linear distance measuring device. As an integrated system, they allow the data collection vehicle to accurately maintain submeter vehicle position even if GPS signals are lost for up to 10 minutes. This means that mapping in cities with tall buildings and significant tree canopies as well as inside tunnels is now possible.

Using digital cameras with pixel resolution of 1024 x 768 with full frame progressive scanning technology, the GPSVision system produces high quality stereo digital imagery. The cameras are mounted on top of the vehicle and can be pointed forward, to the side or to the rear depending on the application requirements. Because the cameras cover the same area from different positions, locations of features closer than 40 meters in front of the lenses can be calculated using triangulation algorithms. Once the asset is positioned information about the object can be added easily to the data stream.

Output to GIS or CAD systems is as simple as defining data table cross references and pushing a command button to generate data files for AutoCAD, MicroStation, MGE, ArcInfo, ArcView, Small World and other popular systems. Additional software tools for random viewing, automatic stationing and offsetting features are also available as part of the GPSVision™ suite of programs.