First results from trials on active-passive SAR imaging

This paper presents the preliminary results of synthetic aperture radar (SAR) imaging of the Earth’s surface obtained using both passive and active radar sensors at the same time. The measurement was carried out during a dedicated measurement campaign held in Poland. As part of the exercise, selected region(s) of the Earth’s surface were imaged using the C-band frequency modulation continuous wave (FMCW) active radar, and the DVB-T-based passive radar at the same time. Both radars were mounted on the light manned aircraft. The main goal of this measurement was to test a fusion possibility of the data acquired from both the active and passive SAR imaging taken in different frequency bands. Thanks to various properties of these radar systems such as foliage penetration capabilities of the passive radar operating at the low UHF frequency and/or high resolution of the C-band active radar, and based on different scattering phenomena (forward/backward) - the fusion of both technologies might provide new yet unexplored possibilities for target recognition and classification. What is more, thanks to the different reflection properties of the targets at different frequencies, different waveforms and different geometries used (a monostatic one in the case of active radars, and a bistatic-in the case of passive radars), such a combined configuration may open new opportunities for measuring other target features than in the case of the individual systems operated separately.