Estimating X-band synthetic aperture radar detection of objects obscured by foliage using the DSTO Ingara airborne imaging radar

Estimating the Probability of Detection (P_d) of synthetic aperture radar (SAR) imagery of foliage-obscured objects requires a knowledge of the object backscatter and the obscuration properties of the foliage. At X-band frequencies minimal penetration of the foliage occurs and as such the assumption that the object is visible only through gaps in the foliage can be made. Given this assumption this paper discusses the use of Hemispherical Canopy Photographs (HCPs) and SAR imagery of unobscured objects to estimate the P_d of obscured objects. These estimates are compared with P_ds measured directly from imagery of obscured objects. The results of this comparison show good agreement between the estimated and measured P_d values, indicating that a knowledge of the particular object backscatter and the HCP of a particular obscuration scenario is sufficient to predict the P_d without the need to image the obscured object directly