A novel approach for wide‐swath and high‐resolution SAR image generation from distributed small spaceborne SAR systems

In this paper we investigate the possibility to produce high‐resolution synthetic aperture radar (SAR) images of wide areas from the data collected by the distributed small spaceborne SAR systems. In particular, we focus on the data processing techniques for overcoming the Doppler ambiguity effects characterizing ground echoes and achieving high‐resolution SAR images of wide areas. A novel approach is proposed, the key idea of which is to retrieve the unambiguous azimuth wide (full) spectrum signal from the received ground echoes by using a space–time adaptive processing (STAP) algorithm to overcome the Doppler aliasing effect induced by the lower pulse repetition frequency (PRF); following this operation, conventional SAR data processing tools can be applied to fully focus the SAR images. The STAP‐based approach has the advantages of simplicity, robustness and high efficiency. We also discuss the array configuration requirements, and give a platform velocity/PRF criterion for array configurations.

[1]  P. Mancini,et al.  Ambiguity Suppression In Sars Using Adaptive Array Techniques , 1991, [Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management.

[2]  J. Aguttes.  The SAR train concept: required antenna area distributed over N smaller satellites, increase of performance by N , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[3]  Richard G. Cobb,et al.  Techsat 21 - A revolutionary concept in distributed space based sensing , 1998 .

[4]  Nathan A. Goodman,et al.  Processing of multiple-receiver spaceborne arrays for wide-area SAR , 2002, IEEE Trans. Geosci. Remote. Sens..

[5]  R. Keith Raney,et al.  Precision SAR processing using chirp scaling , 1994, IEEE Trans. Geosci. Remote. Sens..

[6]  Kiyo Tomiyasu,et al.  Image processing of synthetic aperture radar range ambiguous signals , 1994, IEEE Trans. Geosci. Remote. Sens..

[7]  M. Jin.  High quality spotlight SAR processing algorithm designed for LightSAR mission , 1997, IGARSS'97. 1997 IEEE International Geoscience and Remote Sensing Symposium Proceedings. Remote Sensing - A Scientific Vision for Sustainable Development.

[8]  Alberto Moreira,et al.  Spotlight SAR data processing using the frequency scaling algorithm , 1999, IEEE Trans. Geosci. Remote. Sens..

[9]  M. Tesauro,et al.  Spotlight SAR image generation based on strip mode focusing techniques , 1999, IEEE 1999 International Geoscience and Remote Sensing Symposium. IGARSS'99 (Cat. No.99CH36293).

[10]  M. A. Brown,et al.  Wide-swath SAR , 1992 .

[11]  R. Lacoss.  DATA ADAPTIVE SPECTRAL ANALYSIS METHODS , 1971 .

[12]  F. Rocca,et al.  Spot Mode Sar Focusing With The W - K Technique , 1991, [Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management.

[13]  Maurice Martin,et al.  Distributed satellite missions and technologies - The TechSat 21 program , 1999 .

[14]  Richard Bamler,et al.  PRF-ambiguity resolving by wavelength diversity , 1991, IEEE Trans. Geosci. Remote. Sens..

[15]  I. Longstaff,et al.  Wide-swath space-borne SAR using a quad-element array , 1999 .

[16]  G. Krieger,et al.  Analysis of system concepts for bi- and multi-static SAR missions , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[17]  D. Massonnet,et al.  The interferometric cartwheel: A constellation of passive satellites to produce radar images to be coherently combined , 2001 .

[18]  L. Phalippou,et al.  Preliminary design of the payload for the interferometric cartwheel , 2000, IGARSS 2000. IEEE 2000 International Geoscience and Remote Sensing Symposium. Taking the Pulse of the Planet: The Role of Remote Sensing in Managing the Environment. Proceedings (Cat. No.00CH37120).

[19]  Alberto Moreira,et al.  Extended chirp scaling algorithm for air- and spaceborne SAR data processing in stripmap and ScanSAR imaging modes , 1996, IEEE Trans. Geosci. Remote. Sens..

[20]  Jean Paul Aguttes.  New designs or modes for flexible space borne SAR , 2002, IEEE International Geoscience and Remote Sensing Symposium.

[21]  Giorgio Franceschetti,et al.  A SAR processor based on two-dimensional FFT codes , 1990 .

[22]  S. A. Hovanessian,et al.  Spaceborne radar design equations and concepts , 1997, 1997 IEEE Aerospace Conference.

[23]  Werner Wiesbeck,et al.  Digital beamforming in SAR systems , 2003, IEEE Trans. Geosci. Remote. Sens..

[24]  J. Capon.  High-resolution frequency-wavenumber spectrum analysis , 1969 .

[25]  Michael Y. Jin,et al.  A SAR correlation algorithm which accommodates large-range migration , 1984, IEEE Transactions on Geoscience and Remote Sensing.

[26]  I. Reed,et al.  Rapid Convergence Rate in Adaptive Arrays , 1974, IEEE Transactions on Aerospace and Electronic Systems.

[27]  F. Rocca,et al.  SAR data focusing using seismic migration techniques , 1991 .

[28]  Leopold J. Cantafio,et al.  Space-Based Radar Handbook , 1989 .