2006 Ohio Student Research Forum
Abstract
Examining Performance of GPS ReceiversAnikwenze Ogbue
Ohio State University
Department of Civil Engineering
Mentor: Dr. Charles Toth
The world is very dependent on the NAVSTAR Global Positioning System (GPS) for a variety of functions. Cell phones use the system to verify if the position of the phone is within the network. Also, vehicles such as trucks and ambulances need GPS to navigate efficiently through roadways. In particular, surveyors and geodesists rely on GPS receivers to determine accurate position data. Therefore it is absolutely necessary that they are using equipment that verifies their field data. Furthermore, manufacturers developing global positioning technology are interested in firsthand user critique of their receivers. This research seeks to independently assess three different brands of receivers based on performance: NovAtel DL-4, Topcon Legacy and Trimble 5700.
There were two procedures used to collect position observations. A static procedure involved a setup of four receivers connected to an antenna, which receives a signal from GPS satellites. The setup has two main controls. First, each receiver interprets the signal simultaneously. Second, the antenna is located on the roof of the Center for Mapping building so its position is permanent and does not change. These are important factors that will ensure the static position data is stationary.
A second procedure sought to evaluate kinematic data collection capabilities of the GPS receivers. The team used the GPS Van™ to receive a signal while traveling along local streets. Along the path GPS receivers collect data via an antenna inside the truck.
Final results were processed with software suitable for organizing static and kinematic observations in a comprehensible manner. Then comparisons are made between the position data produced by the different receivers. This assessment is based on a statistical analysis of the position data and the affect of GPS error sources on signal receiving ability. Receivers are then evaluated with respect to one another and with respect to the manufacturers’ claims.
