IIIS - International Institute of Informatics and Systemics
Abstract
The accuracy of the Navigation Satellite Timing and Ranging
(NAVSTAR) Global Positioning System (GPS) measurements is
insufficient for many outdoor navigation tasks. As a result, in
the late nineties, a new methodology – the Differential GPS
(DGPS) – was developed. The differential approach is based on
the calculation and dissemination of the range errors of the GPS
satellites received. GPS/DGPS receivers correlate the
broadcasted GPS data with the DGPS corrections, granting users
increased accuracy. DGPS data can be disseminated using
terrestrial radio beacons, satellites and, more recently, the
Internet.
Our goal is to provide mobile platforms within our campus
with DGPS data for precise outdoor navigation. To achieve this
objective, we designed and implemented a three-tier
client/server distributed system that establishes Internet links
with remote DGPS sources and performs campus-wide
dissemination of the obtained data. The Internet links are
established between data servers connected to remote DGPS
sources and the client, which is the data input module of the
campus-wide DGPS data provider. The campus DGPS data
provider allows the establishment of both Intranet and wireless
links within the campus. This distributed system is expected to
provide adequate support for accurate (submetric) outdoor
navigation tasks
