Measurement and calculation of the bistatic RCS of ground surfaces

The result of a study in a project aimed at finding methods and data for estimating the effects of interaction with background on object signatures are reported. A model surface for ground has been studied using both calculations and measurements. The emphasis has been put on the effects of the surface geometry and therefore a metallic surface was chosen. Measurements have also been made on a more natural model surface, grass lawn. Two methods, IEM and the program SPECRAY using PO supplemented by GO have been used in the calculations. The two methods show a satisfactory agreement. The measured values show a similar trend, but only a qualitative comparison has been made with these. As expected, the grass measurements show differences as well as similarities with the rough metallic model surface. For these measurements a new data collection system and new program code for data analysis have been used together with the bistatic arc for the first time. The results are promising and experiences gained are expected henceforth to allow quantitative comparisons between measured and calculated values.