EMISAR: an absolutely calibrated polarimetric L- and C-band SAR

EMISAR is a high-resolution (2/spl times/2 m), fully polarimetric, dual-frequency (L- and C-band) synthetic aperture radar (SAR) system designed for remote-sensing applications. The SAR is operated at high altitudes on a Gulfstream G-3 jet aircraft. The system is very well calibrated and has low sidelobes and low cross-polar contamination. Digital technology has been utilized to realize a flexible and highly stable radar with variable resolution, swath width, and imaging geometry. Thermal control and several calibration loops have been built into the system to ensure system stability and absolute calibration. Accurately measured antenna gains and radiation patterns are included in the calibration. The processing system is developed to support data calibration, which is the key to most of the current applications. Recent interferometric enhancements are important for many scientific applications.

[1]  J. J. Mohr,et al.  Parametric estimation of time varying baselines in airborne interferometric SAR , 1996, IGARSS '96. 1996 International Geoscience and Remote Sensing Symposium.

[2]  W. Brown.  Synthetic Aperture Radar , 1967, IEEE Transactions on Aerospace and Electronic Systems.

[3]  Søren Nørvang Madsen,et al.  A system for airborne SAR interferometry , 1996 .

[4]  L. T. Pedersen,et al.  Polarimetric signatures of sea ice in the Greenland Sea , 1995, 1995 International Geoscience and Remote Sensing Symposium, IGARSS '95. Quantitative Remote Sensing for Science and Applications.

[5]  Søren Nørvang Madsen,et al.  The Danish real-time SAR processor: first results , 1993, Proceedings of IGARSS '93 - IEEE International Geoscience and Remote Sensing Symposium.

[6]  P. Gudmandsen,et al.  Calibration and modelling of MAESTRO 1 polarimetric SAR data of a forest area in Les Landes, France , 1994 .

[7]  H. Skriver,et al.  Estimating soil moisture using the Danish polarimetric SAR , 1995, 1995 International Geoscience and Remote Sensing Symposium, IGARSS '95. Quantitative Remote Sensing for Science and Applications.

[8]  Søren Nørvang Madsen,et al.  The Danish SAR system: design and initial tests , 1991, IEEE Trans. Geosci. Remote. Sens..

[9]  J. Zyl.  Calibration of polarimetric radar images using only image parameters and trihedral corner reflector responses , 1990 .

[10]  R. Bamler,et al.  A plea for radar brightness , 1994, Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium.

[11]  J. Granholm,et al.  Microstrip antenna for polarimetric C-band SAR , 1994, Proceedings of IEEE Antennas and Propagation Society International Symposium and URSI National Radio Science Meeting.

[12]  J. Kong,et al.  Theoretical models for polarimetric radar clutter , 1987 .

[13]  Niels Skou,et al.  A high resolution polarimetric L-band SAR-design and first results , 1995, 1995 International Geoscience and Remote Sensing Symposium, IGARSS '95. Quantitative Remote Sensing for Science and Applications.

[14]  A. Netterstrom,et al.  Correction for quadrature errors , 1994, Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium.

[15]  Søren Nørvang Madsen,et al.  Real-time processor for the Danish airborne SAR , 1992 .

[16]  N. Skou,et al.  Pulse-based internal calibration of polarimetric SAR , 1994, Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium.

[17]  E. L. Christensen,et al.  SAR antenna design for ambiguity and multipath suppression , 1993, Proceedings of IGARSS '93 - IEEE International Geoscience and Remote Sensing Symposium.

[18]  Anthony Freeman,et al.  SAR calibration: an overview , 1992, IEEE Trans. Geosci. Remote. Sens..

[19]  H. Skriver,et al.  External polarimetric calibration of the Danish polarimetric C-band SAR , 1994, Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium.

[20]  Thuy Le Toan,et al.  Dependence of radar backscatter on coniferous forest biomass , 1992, IEEE Trans. Geosci. Remote. Sens..

[21]  A Oy,et al.  Synthetic Aperture Radar Calibration Using Reference Reflectors , 1990 .

[22]  J. Granholm,et al.  Cross-polarization and sidelobe suppression in dual linear polarization antenna arrays , 1997 .

[23]  J. Klein.  Calibration of complex polarimetric SAR imagery using backscatter correlations , 1992 .

[24]  H. Kramer.  Observation of the Earth and Its Environment: Survey of Missions and Sensors , 1994 .

[25]  Diane L. Evans,et al.  Approach to derivation of SIR-C science requirements for calibration , 1992, IEEE Trans. Geosci. Remote. Sens..

[26]  T. Nielsen,et al.  Geologic mapping in Greenland with polarimetric SAR , 1995, 1995 International Geoscience and Remote Sensing Symposium, IGARSS '95. Quantitative Remote Sensing for Science and Applications.

[27]  Shaun Quegan,et al.  A unified algorithm for phase and cross-talk calibration of polarimetric data-theory and observations , 1994, IEEE Trans. Geosci. Remote. Sens..