Session: Scientific Achievements, Applications, and Future Requirements

In Space Geodesy, scientific achievements and applications using Satellite Laser Ranging (SLR) data have been obtained and developed in many fields: orbitography, Earth rotation and geocentric reference frame, geodynamics, determination of long wave lengths of the gravity field and of the geocentric gravitational constant (GM), calibration/validation of products in space oceanography, time transfer, space debris control,…. But, in parallel, the radioelectric techniques (GPS, DORIS, PRARE) made so important progress in efficiency and precision that the role of SLR technique has to be repositioned and specified. In fact we would like to recall that in many fields the role of SLR appears to be irreplaceable, such as for the determination of the first spherical harmonics and of the geocentric gravitational constant, the long term sea level monitoring through actions of calibration and validation of the oceanographic satellite,…. Stopping the SLR technique would be a disaster in fundamental metrology of the Space Geodesy. However SLR has to be competitive in terms of accuracy, efficiency, and cost. This technique has to be maintained at its highest level and to be improved continuously as carried out by the ILRS (for example permanent and fast quality control with feedback to the stations). Other improvements are to be considered: laser systems with high frequency rate and very small energy, automation of stations, development of two–color laser systems,…. General comments are given