Filtering approaches for interference suppression in low-frequency SAR

Low-frequency synthetic aperture radar (SAR) systems are of interest primarily because of their ability to see through foliage for a variety of purposes. Unfortunately, the very high frequency/ultra-high frequency bands are used by a large number of services such as television, radio and communications. The authors describe a number of different radio frequency interference suppression techniques that have been investigated and that were tested on wide bandwidth low-frequency SAR data collected on board a helicopter using the Airborne Data Acquisition System (ADAS) low-frequency radar. The least-mean-square (LMS) filter and the Wiener filter are both investigated in detail. The adaptive Wiener filter is found to have superior suppression and sidelobe performance and is also computationally much faster than the LMS filter when applied to the ADAS data.

[1]  James M. Ralston,et al.  Signal processing approaches to radio frequency interference (RFI) suppression , 1994, Defense, Security, and Sensing.

[2]  Athanasios Papoulis,et al.  Probability, Random Variables and Stochastic Processes , 1965 .

[3]  W. Carrara,et al.  Spotlight synthetic aperture radar : signal processing algorithms , 1995 .

[4]  Diannong Liang,et al.  Gradual RELAX algorithm for RFI suppression in UWB-SAR , 1999 .

[5]  Bruce H. Ferrell.  Interference suppression in UHF synthetic aperture radar , 1995, Defense, Security, and Sensing.

[6]  Walter G. Carrara,et al.  Spotlight Synthetic Aperture Radar , 1995 .

[7]  R. P. Maloney,et al.  Technical challenges in ultra-wideband radar development for target detection and terrain mapping , 1999, Proceedings of the 1999 IEEE Radar Conference. Radar into the Next Millennium (Cat. No.99CH36249).

[8]  J. Fleischman,et al.  Foliage attenuation and backscatter analysis of SAR imagery , 1996, IEEE Transactions on Aerospace and Electronic Systems.

[9]  Lars M. H. Ulander,et al.  RFI suppression in ultra-wideband SAR systems using LMS filters in frequency domain , 2001 .

[10]  Michael Inggs,et al.  Efficient RFI suppression in SAR using LMS adaptive filter integrated with range/Doppler algorithm , 1999 .

[11]  L. Potter,et al.  RFI suppression for ultra wideband radar , 1997, IEEE Transactions on Aerospace and Electronic Systems.

[12]  J. Fleischman,et al.  Analysis of foliage-induced synthetic pattern distortions , 1996, IEEE Transactions on Aerospace and Electronic Systems.

[13]  R. S. Vickers.  Design and applications of airborne radars in the VHF/UHF band , 2002 .

[14]  S. M. Crooks,et al.  P-3 ultra-wideband SAR, Grayling, Michigan, target and clutter phenomenology , 1999, Proceedings of the 1999 IEEE Radar Conference. Radar into the Next Millennium (Cat. No.99CH36249).

[15]  S. Haykin,et al.  Adaptive Filter Theory , 1986 .

[16]  Serpil Ayasli,et al.  SAR foliage penetration phenomenology of tropical rain forest and northern US forest , 1995, Proceedings International Radar Conference.

[17]  Jon Hamkins.  An analytic technique to separate cochannel FM signals , 2000, IEEE Trans. Commun..