Multi wavelength optical broad band photometric properties of a representative sample of geostationary satellites

We present the results of multi-wavelength optical observations, using B, V, R and I band filters, of a sample of 61 active geostationary communications satellites, on 2015 July 9-11. These observations were done outside the glinting season, with a longitudinal solar angle smaller than 6° and a latitudinal solar phase angle of ∼16.5°. This approach enabled us to detemine the distribution of quiescent magnitudes and colors of these targets during a period of the night when they are expected to be the brightest. We present the distribution of magnitudes and colors of the sample. We find that the colors of these satellites are in general redder than the Solar spectrum, with a wide distribution of values (0.62<B-V<1.49,1.00<B-R<2.28,1.31<B-I<3.07,0.34<V-R<0.90,0.63<V-I<1.69,0.27<R-I<0.79). Satellites from different manufacturers are found to cluster around specific colors in color-color plots, indicating that this information can be used to identify different satellites and resolve cross tagging issues. We also invetigate whether the colors of satellites change with time and find that in most cases there is no significant change to these properties as the satellites age.

Source: Advances in Space Research - September 28, 2019 Category: Science Source Type: research