Laser measurements to space debris from Graz SLR station

Abstract

In order to test laser ranging possibilities to space debris objects, the Satellite Laser Ranging (SLR) Station Graz installed a frequency doubled Nd:YAG pulse laser with a 1kHz repetition rate, a pulse width of 10ns, and a pulse energy of 25mJ at 532nm (on loan from German Aerospace Center Stuttgart – DLR). We developed and built low-noise single-photon detection units to enable laser ranging to targets with inaccurate orbit predictions, and adapted our standard SLR software to include a few hundred space debris targets. With this configuration, we successfully tracked – within 13 early-evening sessions of each about 1.5h – 85 passes of 43 different space debris targets, in distances between 600km and up to more than 2500km, with radar cross sections from >15m2 down to <0.3m2, and measured their distances with an average precision of about 0.7m RMS.