Fig. 6: Noise distribution.
From: Space debris and satellite laser ranging combined using a megahertz system
Histogram distribution of the background noise level of all successful space debris laser ranging passes at a 100 kHz monostatic and b 1 MHz bistatic. The noise counts per meter and second (cpms) are plotted with respect to the normalized occurrence. The noise connected to illuminated space debris (blue) for 1 MHz is by a factor of 50-100 larger as compared with 100 kHz. A noise measurement of the sky background (red) reveals the minimal noise level which is present in both distributions. During the sky measurement the laser power was varied periodically without any influence on the noise level, verifying that the receiving station does not detect laser backscatter in bistatic configuration.
