Technical questions concerning base mapping : the use of an image processing system for small scale cartography based on satellite imagery **

Abstract

The main aim of geodesy is to supply a group of points known and marked on the earth’s surface which can be used both for scientific research and for basic surveys and mapping. The Doppler-Fizeau effect is a frequency shift phenomenon affecting signals emitted by a source moving with respect to the observer. Measurement of the frequency difference between the wave that would be received by an observer moving with the mobile emitter and the wave received by the real observer enables one to compute the relative speed of the emitter with respect to the receiver. During recent years the Institute Geographies National, France, has participated in various joint projects described in this report.