The Use of Heuristics in the Design of GPS Networks

Abstract

One aspect of GPS network design concerns the logistics of the survey. Others aspects include location of stations, length of time for session observations. Efficient logistics enables a survey to be carried out with a lower cost and/or shorter time. A significant influence on the efficiency of the survey comes from the order in which the sessions are observed (the schedule). Previous work has shown that, given a list of sessions, the optimal schedule can be determined given the cost of moving receivers between points and the list of sessions. The solution was obtained by transforming the problem into a Multiple Travelling Salesman Problem enabling more than one working period to be included in the solution. However, the method was only suitable for relatively small networks.

To enable larger networks to be solved, the use of heuristic techniques within the field of Operational Research have been investigated. Heuristics enable optimal or near-optimal solutions to be found for very large problems with a reasonable computation time — optimality, however, is not guaranteed. This paper will describe one particular heuristic (Simulated Annealing) and show how it can be applied to the logistics design of GPS networks.