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Operators for the Satellite Laser Ranger join the staff 1999/10/01

The first three operators for the Satellite Laser Ranging (SLR) facility at Hartebeesthoek joined the HartRAO staff on 01 October 1999 to begin training. They are Lesiba Ledwaba, Piet (Solly) Mohlabeng and Marisa Nickola.

The SLR system for Hartebeesthoek is MOBLAS6, from GSFC, Washington, which will be installed on our SLR reference pad early in 2000.

Laser ranging works by firing laser pulses at specific earth-orbiting satellites. The satellites are metal spheres covered in hundreds of cube corner retroreflectors that reflect the laser beam back in the direction from which it came. The travel time of the laser pulses gives the distance to the satellite. Analysis of the results allows the position of the laser transmitter to be determined extremely accurately. This in turn allows factors such as the variation in the earth's daily rotation and the earth's polar motion to be measured.

The location of the SLR at Hartebeesthoek will allow these measurements to be compared with similar results obtained at the same site from radio astronomy (geodetic VLBI) and the Global Positioning System (GPS).