An Azimuth Frequency Non-Linear Chirp Scaling (FNCS) Algorithm for TOPS SAR Imaging With High Squint Angle

During the data acquisition of a squint terrain observation by progressive scan (TOPS) synthetic aperture radar (SAR), the steering of the antenna main beam increases the azimuth bandwidth and results in the azimuth signal aliasing in the Doppler domain. Besides, the range curvature and the Doppler...

Celý popis

Uložené v:
Podrobná bibliografia
Vydané v:IEEE journal of selected topics in applied earth observations and remote sensing Ročník 7; číslo 1; s. 213 - 221
Hlavní autori: Wu, Yufeng, Sun, Guang-Cai, Xia, Xiang-Gen, Xing, Mengdao, Yang, Jun, Bao, Zheng
Médium: Journal Article
Jazyk:English
Vydavateľské údaje: IEEE 01.01.2014
Predmet:
Azimuth
Chirp
Doppler effect
Frequency modulation
Frequency nonlinear chirp scaling
Frequency-domain analysis
full-aperture processing
Imaging
modified chirp scaling algorithm
spectral analysis (SPECAN)
squint TOPS SAR
Synthetic aperture radar
ISSN:1939-1404, 2151-1535
On-line prístup:Získať plný text
Tagy: Pridať tag
Žiadne tagy, Buďte prvý, kto otaguje tento záznam!
Popis
Shrnutí:During the data acquisition of a squint terrain observation by progressive scan (TOPS) synthetic aperture radar (SAR), the steering of the antenna main beam increases the azimuth bandwidth and results in the azimuth signal aliasing in the Doppler domain. Besides, the range curvature and the Doppler frequency modulation (FM) rates after linear range walk correction are azimuth-variant for squint TOPS SAR. These problems may cause some difficulties for the SAR data processing. To deal with the problems, a new imaging algorithm for the squint TOPS SAR is introduced in this paper. After linear range walk correction, the azimuth preprocessing is implemented to achieve the two-dimensional frequency spectrum without aliasing. Then, utilizing a modified chirp scaling algorithm, we complete the range cell migration correction (RCMC) and range compression to the TOPS SAR data without subaperture. Finally, the frequency nonlinear chirp scaling (FNCS) is proposed to correct the variation of the FM rates and the azimuth signal is focused in the Doppler domain via the spectral analysis (SPECAN) method. Both simulation and real data results show the effectiveness of the proposed algorithm.
ISSN:1939-1404
2151-1535
DOI:10.1109/JSTARS.2013.2258893