A DBS Doppler Centroid Estimation Algorithm Based on Entropy Minimization

Doppler centroid is a key focusing parameter of Doppler beam sharpening (DBS) imaging. According to the locked relationship between Doppler centroid error and image entropy, a minimum-entropy Doppler estimator (MEDE) is proposed. The algorithm breaks the conventional algorithms' assumption that the shape of echo signal's power spectrum is symmetrical, and the proposed method can circumvent the problem of low estimation precision using conventional algorithms to process the echo signal from high-scene contrast. The new algorithm based on entropy minimization has high estimation precision in the case of low- and high-scene contrast. MEDE has been successfully applied to a DBS real-time imaging processor of airborne radar and verified by flight experiments.

[1]  E Qin.  On Coupling Effect of Two Vortex Systems of Chinese Aircraft with TurboPropellers , 1997 .

[2]  Michael Y. Jin.  Optimal range and Doppler centroid estimation for a ScanSAR system , 1996, IEEE Trans. Geosci. Remote. Sens..

[3]  Fabrizio Argenti,et al.  Segmentation-Based MAP Despeckling of SAR Images in the Undecimated Wavelet Domain , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[4]  F. Berizzi,et al.  Autofocusing of inverse synthetic aperture radar images using contrast optimization , 1996, IEEE Transactions on Aerospace and Electronic Systems.

[5]  Zheng Bao,et al.  Doppler Ambiguity Resolving in Compressed Azimuth Time and Range Frequency Domain , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[6]  Fabio Rocca,et al.  Blind deconvolution for Doppler centroid estimation in high frequency SAR , 1991, IEEE Trans. Geosci. Remote. Sens..

[7]  Richard Bamler,et al.  Doppler frequency estimation and the Cramer-Rao bound , 1991, IEEE Trans. Geosci. Remote. Sens..

[8]  Ian G. Cumming,et al.  A spatially selective approach to Doppler estimation for frame-based satellite SAR processing , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[9]  Weidong Yu,et al.  Comparison of Doppler centroid estimation methods in SAR , 1997, Proceedings of the IEEE 1997 National Aerospace and Electronics Conference. NAECON 1997.

[10]  Shu Li,et al.  Adding Sensitivity to the MLBF Doppler Centroid Estimator , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[11]  John C. Curlander,et al.  Application of the multiple PRF technique to resolve Doppler centroid estimation ambiguity for spaceborne SAR , 1992, IEEE Trans. Geosci. Remote. Sens..

[12]  Kush R. Varshney,et al.  Sparse Representation in Structured Dictionaries With Application to Synthetic Aperture Radar , 2008, IEEE Transactions on Signal Processing.

[13]  Hong Gu,et al.  The study on Doppler centroid estimation in DBS imaging , 2001, 2001 CIE International Conference on Radar Proceedings (Cat No.01TH8559).

[14]  J. P. Ruina,et al.  Some Early Developments in Synthetic Aperture Radar Systems , 1962, IRE Transactions on Military Electronics.

[15]  Ian G. Cumming,et al.  Signal properties of spaceborne squint-mode SAR , 1997, IEEE Trans. Geosci. Remote. Sens..

[16]  Junfeng Wang,et al.  SAR Minimum-Entropy Autofocus Using an Adaptive-Order Polynomial Model , 2006, IEEE Geoscience and Remote Sensing Letters.

[17]  M. E. Radant.  The evolution of digital signal processing for airborne radar , 2002 .

[18]  Oliver Montenbruck,et al.  TerraSAR-X Precise Trajectory Estimation and Quality Assessment , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[19]  Gianfranco Fornaro,et al.  Detection of Single Scatterers in Multidimensional SAR Imaging , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[20]  A. Britton,et al.  Millimetre wave radar imaging , 1994 .

[21]  Yinqing Zhou.  Doppler beam sharping technique for airborne pulse Doppler radar , 1988 .

[22]  Oleksandr O. Bezvesilniy,et al.  Retrieving 3-D Topography by Using a Single-Antenna Squint-Mode Airborne SAR , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[23]  Mengdao Xing,et al.  Motion Compensation for UAV SAR Based on Raw Radar Data , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[24]  Gerhard Krieger,et al.  Total zero Doppler Steering-a new method for minimizing the Doppler centroid , 2005, IEEE Geoscience and Remote Sensing Letters.

[25]  John Kirk.  A Discussion of Digital Processing in Synthetic Aperture Radar , 1975, IEEE Transactions on Aerospace and Electronic Systems.

[26]  Jørgen Dall,et al.  Sea-Ice Deformation State From Synthetic Aperture Radar Imagery—Part I: Comparison of C- and L-Band and Different Polarization , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[27]  K. Kulpa,et al.  Real-time implementation of doppler beam sharpening technique with simple motion estimation , 2004, First European Radar Conference, 2004. EURAD..

[28]  C. Wiley.  Synthetic Aperture Radars , 1985, IEEE Transactions on Aerospace and Electronic Systems.

[29]  Charles V. Jakowatz,et al.  Phase gradient autofocus-a robust tool for high resolution SAR phase correction , 1994 .

[30]  Michael Jin.  Optimal Doppler Centroid Estimation for SAR Data from a Quasi-Homogeneous Source , 1986, IEEE Transactions on Geoscience and Remote Sensing.

[31]  Young-Kyun Kong,et al.  Ambiguity-free Doppler centroid estimation technique for airborne SAR using the Radon transform , 2005, IEEE Transactions on Geoscience and Remote Sensing.

[32]  Anthony Freeman,et al.  The Prediction of Geometric Distortions in Airborne Synthetic Aperture Radar Imagery from Autofocus Measurements , 1987, IEEE Transactions on Geoscience and Remote Sensing.

[33]  Fuk K. Li,et al.  Doppler Parameter Estimation for Spaceborne Synthetic-Aperture Radars , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[34]  Li Xi,et al.  Autofocusing of ISAR images based on entropy minimization , 1999 .