Collaborative positioning in GPS-challenged environments

GPS augmentation in the form of multi-sensor systems is an accepted approach to positioning in GPS-challenged environments. An extension of this is the concept of collaborative or cooperative positioning, through which a network of GPS users may collectively receive any available satellite signals, augmented by inter-nodal ranging and other sensory measurements to achieve joint and potentially improved position determination. This paper presents an analysis of CP techniques for robust GPS positioning in vehicular ad-hoc networks (VANETs) based around the availability of dedicated short range communications infrastructure (DSRC). Preliminary performance assessments based on simulated and field data collected at the Ohio State University in November 2011 verify that the CP algorithm developed here offers improved accuracy compared to a CP solution that uses standalone GPS positions: 50 % improvement for the duration of the OSU test and 38 % with outages simulated to represent periods of 100 % satellite unavailability