Atmospheric Correction and Multiwavelength
V. Luceri and S. Riepl
|Title of Paper
|Two-Wavelength Satellite Laser Ranging Experiment at Shanghai
|Real-Time Separation Atmospheric Tip-Tilt Signal from Lunar
|Effects of the Atmosphere on the SLR Precision
|Atmospheric Contribution to the Laser Ranging Jitter
|The Correction of SLR Data by the Nonlinear Dispersion of the
Refraction Index of the Air
|Multiwavelength Refraction Modeling Improvements for SLR Observations
The session on atmospheric correction and multi wavelength ranging started with a contribution concerning the dual wavelength Raman approach at Shanghai observatory, which reported successful acquisition of LEO satellites in two colour mode: experiment started on July 2003 and more than 20 passes tracked. New plans include the acquisition of a new counter and the improvement of the Raman output energy.
The second presentation dealt with an adaptive optics experiment carried out at Yunnan Observatory. It aims at the improvement of the LLR link budget by deriving a tip tilt correction signal from lunar surface images, gathered in real time, in order to drive a compensating mirror which improves the effective transmit laser pointing stability.
Two contributions were related to the turbulence induced ranging jitter. Taking advantage of the Graz 2 kHz laser ranging facility, experiments employing a variety of ground and spaceborne targets have been carried out. Main goals were the modelling of the atmospheric turbulence and the measure of its influence on the ranges. In parallel seeing measurements were taken in order to reveal possible correlations between atmospheric conditions and turbulence-induced ranging jitter .
The session was closed by a poster presentation related to the atmospheric refraction modelling which indicated the necessity to improve both the spatial sampling resolution of atmospheric data and the spectral sampling resolution of refractivity measurements, for a better understanding of the group velocity concept applied in SLR.