Low Cost Differential GPS Receivers (LCD-GPS): The Differential Correction Function

Wireless Sensor Networks (WSN) are used in many applications such as environmental data collection, smart home, smart care and intelligent transportation system. Sensor nodes composing the WSN cooperate together in order to monitor physical entities such as temperature, humidity, sound, atmospheric pressure, motion or pollutants at different locations. To have location information, it is possible to configure nodes with their locations, in small deployments, but in large-scale deployments or when the nodes are mobile, the use of GPS is very interesting. However, the current accuracy of standard civil GPS is not sufficient for all WSN applications. Indeed, GPS measurements suffer from many errors especially in city. To improve GPS accuracy the differential mode (DGPS) has been introduced. In this paper, we present a WSN used to provide a DGPS solution. It´s consisting of a set of low cost standard civil GPS communicating receivers. We present the design, implementation and some experimental results of this solution.