Extension of the chirp scaling algorithm to 3-D near-field wideband radar imaging

The objective of the present work is the development of an efficient algorithm to focus two-dimensional SAR images under the following extreme conditions: large co- herent integration angles and high bandwidth-to-centre- frequency ratios (B/fc). These conditions constitute a common situation in wide-band high-resolution SAR con- figurations. The algorithm presented in this paper is an extension of the well-known chirp scaling algorithm (CSA). First, the original 2-D CSA (1) is generalized by extending the formulation from data obtained with a linear aperture to data measured by a planar synthetic aperture. Moreover, a new compact generalized formula of the impulse response function in the three-dimensional frequency domain is pre- sented. These extensions enable the development of a new 3-D algorithm in the aforementioned conditions. Finally, the algorithm has been implemented and satisfactory tested.