This new electronic surveying instrument measures s/ope distance and zenith angle simultaneously, then computes and displays horizontal or vertical distance in feet or metres. /fs base measures horizontal angle. f N 1e70, WITH THE INTRODUCTION of the I saooA Distance Meter. Hewlett-Packard launched into the electronic measurement of distance. Since that time HP has become a major supplier of el...

The Global Positioning System (GPS), originally designed for navigation purposes, has shown its capabilities for use in atmospheric studies for over a decade now (e.g., Bevis et al. 1992). Atmospheric delays of the GPS signals, caused by the atmospheric refractivity along the ray path to a ground-based receiver, are used as tracers of atmospheric densities. The delay caused by the electrically ...