Title :
The Application of the Principle of Chirp Scaling in Processing Stepped Chirps in Spotlight SAR
Author :
Nie, Xin ; Zhu, Daiyin ; Mao, Xinhua ; Zhu, Zhaoda
Author_Institution :
Coll. of Inf. Sci. & Technol., Nanjing Univ. of Aeronaut. & Astronaut., Nanjing, China
Abstract :
A new approach to process stepped chirps in spotlight synthetic aperture radar is presented in this letter, which is based on exploiting the principle of chirp scaling (PCS). In particular, PCS is integrated into the polar format algorithm (PFA), obtaining a more efficient solution compared with the existing polar interpolation technique. The main contribution of this letter is the implementation of azimuth scaling, in which the bandwidth synthesis is embedded. The algorithm is developed dedicatedly for dealing with stepped chirps. The signal processing flow is investigated in detail, in which no interpolations but only fast Fourier transform and complex multiplications are involved. Point-target simulation has validated the new approach and indicated that it is more efficient than the classic interpolation-based one. The achieved computational gain measured in execution time is around 25%-30%.
Keywords :
fast Fourier transforms; interpolation; radar imaging; synthetic aperture radar; PCS; PFA; azimuth scaling; bandwidth synthesis; classic interpolation-based technique; complex multiplication; computational gain measurement; fast Fourier transform; point-target simulation; polar format algorithm; polar interpolation technique; principle-of-chirp scaling; signal processing flow; spotlight SAR imaging; stepped chirp processing; synthetic aperture radar; Azimuth scaling; polar format algorithm (PFA); principle of chirp scaling (PCS); spotlight synthetic aperture radar (SAR); stepped chirps;
Journal_Title :
Geoscience and Remote Sensing Letters, IEEE
DOI :
10.1109/LGRS.2009.2027212
