Performance of differential GPS based on a real-time algorithm using SMS services of GSM network

A real-time simple algorithm of differential GPS is adopted tested experimentally using an existing GSM network utilizing SMS service that takes short time with low cost. A system of DGPS is designed and implemented. The implemented system includes basically reference station (RS) and mobile station (MS). The RS consists of a personal computer (PC_A) with a GPS receiver and a modem of GSM. The differential data (DD) between the GPS reading and the original position of RS is determined and sent to MS via GSM modem. The mobile station consists also of a GPS receiver and a GSM modem connected with a personal computer (PC_B). The DD is received by GSM modem and compared with the GPS readings at MS to determine the exact position of the mobile station. The system is tested experimentally and a horizontal accuracy of 0.44m and a vertical accuracy of 0.55m are obtained.