Velocity Estimation Method Considering Doppler Effect and PSO Based Algorithm for Satellites Constellation IRNSS and GPS

Abstract

In this work, a method for velocity estimation of the user is done using a GPS-IRNSS/NavIC/ SBAS (IGS) receiver. With the help of the receiver in a moving vehicle, dynamic data is logged continuously in IRNSS/ NavIC+GPS hybrid operation to get receiver’s coordinates, Geometric dilution of precision (GDOP) and receiver’s velocity. The logged values of receiver’s coordinate contain errors, which is minimized first considering Satellite Selection Algorithm (SSA) based on GDOP values and then by applying PSO based algorithm to reduce Doppler shift effect and receiver’s clock offset. After improvement of dynamic receiver’s coordinates for each observation, velocity of receiver is calculated. Results show that velocity obtained using this estimation technique is more accurate in comparison to the velocity information provided by the IGS receiver. This finds major applications in real time vehicle tracking for various applications. In addition, atmospheric delays are expressed here in terms of Doppler shift.