Proceedings of the Symposium on Surveillance and Monitoring Surveys held at [the Dept of Surveying, Univ of Melbourne, Australia], Nov 1986/ by Symposium on Surveillance and Monitoring Surveys( 1986: Univ of Melbourne, Aust), University of Melbourne. Department of Surveying and Land Information, Institution of Surveyors (Australia) Victorian Division, Victorian Society for Photogrammetry and Remote Sensing