GPS has found its way into many applications, mainly as a result of its accuracy, global availability, and cost-effectiveness. Unfortunately, however, there exist some situations in which part of the GPS signal may be obstructed to the extent that the GPS receiver may not "see" enough satellites for positioning. Examples of those situations are positioning in urban canyons and deep open-pit mining. This signal-obstruction problem, however, was successfully overcome by integrating GPS with other positioning systems. In fact, reported results showed that the performance of the integrated system is better than either system alone. Augmenting GPS is not limited to sensor integration. As shown below, GPS can be augmented with computer-based tools, such as GIS, for efficient data collection and analysis.
A geographic information system (GIS) is a computer-based tool capable of acquiring, storing, manipulating, analyzing, and displaying spatially referenced data Spatially referenced data is data that is identified according to its geographic location (e.g., features such as streets, light poles, and fire hydrants are linked by geography).
GPS is used to collect the GIS field data efficiently and accurately With GPS, the data is collected in a digital format in either real-time or postprocessed mode. A number of GPS/GIS systems that provide centimeter- to meter-level accuracy are now available on the market. Most of these systems allow the user to enter user-defined attributes for each feature. Built-in navigation functions to relocate field assets are also available. Pen computer-based systems are used by some GPS receiver manufacturers to allow the data to be edited and displayed as it is collected
Many industries, including utilities management, forestry, agriculture, public safety, and fleet management, can benefit from integrated GPS/GIS systems.