A single SAR image gives a view of the earth's surface, with little height or motion information. The concept of SAR Interferometry, or InSAR, is to use a second, registered SAR image to extract information about the height and/or motion of reflectors on the earth's surface.

InSAR processing begins by registering the two single-look complex SAR images, then forming an interferogram by multiplying one image by the complex conjugate of the other image. The phase of the interferogram represents the fine-scale differences in range to the scattering centres of each pixel. These differences can be caused by topography combined with the parallax between the two viewing directions, or by objects in the scene which have moved between the time that the two images were taken. An interesting research topic is to develop ways to separate the phase changes due to topography from those due to motion, so that topographic and/or motion maps can be made.

Our research at UBC includes the development of better InSAR processing algorithms, such as registration, coherence estimation and phase unwrapping. In addition, we are extracting the motion fields of alpine glaciers, and are using overlapping interferograms and coarse digital elevation models to calibrate the geometry of the satellites and to facilitate phase unwrapping. We are also using along-track interferometry to enhance the detectability of vessels in the ocean.

RRSG Interferometry Papers

[1]

I. G. Cumming and A. L. Gray. Interferometric Radar: A Better Tool for Exploration Geology ? In Seventh Thematic Conference on Remote Sensing for Exploration Geology, pages 561-571, Calgary, Alberta, Canada, 1989.

[2]

I. G. Cumming, D. Hawkins, and A. L. Gray. All-weather Mapping with Interferometric Radar. In 23rd International Symposium on Remote Sensing of the Environment, Bangkok, April 1990.

[3]

D. R. Stevens, I. G. Cumming, A. L. Gray, and M. R. Ito. Airborne Interferometric SAR: Flight Motion Induced Height Errors. In Proceedings of the ARPA Interferometric SAR Technology and Applications Symposium, pages 403-420, Fort Belvoir, VA, April 13-14, 1993.

[4]

D. R. Stevens, I. G. Cumming, A. L. Gray, and M. R. Ito. Airborne Interferometric SAR: Terrain Induced Phase Errors. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'93, pages 977-979, Kogakuin University, Tokyo, Japan, August 17-21, 1993.

[5]

M. S. Seymour and I. G. Cumming. Maximum Likelihood Estimation for SAR Interferometry. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'94, pages 2272-2275, Pasadena, California, August 8-12, 1994.

[6]

D. R. Stevens, I. G. Cumming, and A. L. Gray. Motion Compensation for Airborne Interferometric SAR. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'94, pages 1967-1970, Pasadena, California, August 8-12, 1994.

[7]

D. R. Stevens, I. G. Cumming, and A. L. Gray. Options for Airborne Interferometric SAR Motion Compensation. IEEE Transactions on Geoscience and Remote Sensing, 33(2): pp. 409-420, March 1995.

[8]

J.-L. Valero and I. G. Cumming. A Survey of Phase Unwrapping Techniques, with Applications to InSAR. Technical Report JL-95-1, Radar Remote Sensing Group, Dept. of Electrical Engineering, The University of British Columbia, May 1995.

[9]

T. Ngo and I. G. Cumming. Background Theory and Literature Survey of Current Progress in SAR Along-Track Interferometry. Technical Report TN-95-2, Radar Remote Sensing Group, Dept. of Electrical Engineering, The University of British Columbia, October 1995.

[10]

I. H. McLeod, I. G. Cumming, and M. S. Seymour. ENVISAT ASAR Data Reduction: Impact on SAR Interferometry. IEEE Trans. Geoscience and Remote Sensing, Submitted for publication, December 1995.

[11]

P. W. Vachon, D. Geudtner, K. Mattar, A. L. Gray, M. Brugman, and I. G. Cumming. Differential SAR Interferometry Measurements of Athabasca and Saskatchewan Glacier Flow Rate. Canadian J. of Remote Sensing, Submitted for publication, May 1996, accepted September 1996.

[12]

I. G. Cumming, J.-L. Valero, P. W. Vachon, M. Brugman, K. Mattar, D. Geudtner, M. S. Seymour, and A. L. Gray. Results of ERS Interferometry Measurements of Alpine Glaciers. In Proceedings of the 18th Annual Symposium of the Canadian Remote Sensing Society, pages 324-329, Vancouver, B.C., March 25-29, 1996.

[13]

M. S. Seymour and I. G. Cumming. Satellite SAR Interferometry Mapping Experiments in British Columbia. In Proceedings of the 18th Annual Symposium of the Canadian Remote Sensing Society, pages 315-319, Vancouver, B.C., March 25-29, 1996.

[14]

M. S. Seymour and I. G. Cumming. An Iterative Method for Estimating Baseline Geometry. In Proceedings of the Progress in Electromagnetics Research Symposium, PIERS'96, page 394, Innsbruck, Austria, July 8-12, 1996.

[15]

W. Xu and I. G. Cumming. A Region-Growing Algorithm for InSAR Phase Unwrapping. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'96, pages 2044-2046, Lincoln, Nebraska, May 27-31, 1996.

[16]

J.-L. Valero and I. G. Cumming. Comparative Analysis of Phase Unwrapping Methods Using Self-Affine (Fractal) Models. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'96, pages 336-338, Lincoln, Nebraska, May 27-31, 1996.

[17]

P. W. Vachon, D. Geudtner, A. L. Gray, K. Mattar, M. Brugman, I. G. Cumming, and J.-L. Valero. Airborne and Spaceborne SAR Interferometry: Application to the Athabasca Glacier Area. In Proceedings of the International Geoscience and Remote Sensing Symposium, IGARSS'96, pages 2255-2257, Lincoln, Nebraska, May 27-31, 1996.

[18]

K. E. Mattar, D. Geudtner, A. L. Gray, P. W. Vachon, M. Brugman, I. G. Cumming, and J.-L. Valero. Glacier Flow Field Measurements Using Airborne and Satellite SAR Interferometry. In JPL Workshop on Glaciological Applications of Satellite Radar Interferometry, Pasadena, CA, March 28-29, 1996.

[19]

M. Brugman, I. G. Cumming, J.-L. Valero, M. S. Seymour, P. W. Vachon, and A. L. Gray. Tracking the Pulse of Western Canadian Glaciers using SAR Interferometry and Traditional Methods: Testing the Application to Glacier Flow and Volume Change at Columbia Icefield since 1950. In JPL Workshop on Glaciological Applications of Satellite Radar Interferometry, Pasadena, CA, March 28-29, 1996.

[20]

M. S. Seymour and I. G. Cumming. An iterative algorithm for ERS baseline estimation. In ESA Workshop on Applications of ERS SAR Interferometry, Remote Sensing Laboratories, University of Zurich, Switzerland, 30 Sept - 2 Oct, 1996. Published at http://www.geo.unizh.ch/rsl/fringe96/.

[21]

Wei Xu and Ian Cumming. Unwrapping the difficult Sardegna interferogram. In ESA Workshop on Applications of ERS SAR Interferometry, Remote Sensing Laboratories, University of Zurich, Switzerland, 30 Sept - 2 Oct, 1996. Published at http://www.geo.unizh.ch/rsl/fringe96/.

[22]

Ian Cumming, Juan-Luis Valero, Michael Seymour, Paris Vachon, Karim Mattar, Dirk Geudtner, and Laurence Gray. Glacier flow measurements with ERS tandem mission data. In ESA Workshop on Applications of ERS SAR Interferometry, Remote Sensing Laboratories, University of Zurich, Switzerland, 30 Sept - 2 Oct, 1996. Published at http://www.geo.unizh.ch/rsl/fringe96/.

[23]

Ian Cumming, Juan-Luis Valero, Paris Vachon, Karim Mattar, Dirk Geudtner, and Mindy Brugman. Saskatchewan glacier flow measurements with satellite radar. In NW Glaciologists Meeting, The University of British Columbia, Vancouver, BC, October 25 - 26, 1996.

[24]

W. Xu and I. G. Cumming. Simulator for Repeat-Pass Satellite InSAR Studies -- Functional Description, Users Guide and Test Results. Technical Report WX-96-1, Radar Remote Sensing Group, Dept. of Electrical Engineering, The University of British Columbia, May 1996.

[25]

T. Ngo and I. G. Cumming. Analysis of Coregistraton Methods and Production of Phase Images (Interferograms) for Airborne ATI. Technical Report TN-96-1, Radar Remote Sensing Group, Dept. of Electrical Engineering, The University of British Columbia, March 1996.

[26]

T. Ngo and I. G. Cumming. Comparison of Magnitude and Phase Representations of Ship Wake Features in SAR ATI Interferograms. Technical Report TN-96-2, Radar Remote Sensing Group, Dept. of Electrical Engineering, The University of British Columbia, May 1996.