3-D positioning and target association for medium resolution SAR sensors

Journal Article (2018)
Author(s)

P. Dheenathayalan (TU Delft - Mathematical Geodesy and Positioning)

David Small (Universitat Zurich)

Ramon Hanssen (TU Delft - Mathematical Geodesy and Positioning)

Research Group
Mathematical Geodesy and Positioning
Copyright
© 2018 P. Dheenathayalan, David Small, R.F. Hanssen
DOI related publication
https://doi.org/10.1109/TGRS.2018.2844108
More Info
expand_more
Publication Year
2018
Language
English
Copyright
© 2018 P. Dheenathayalan, David Small, R.F. Hanssen
Research Group
Mathematical Geodesy and Positioning
Issue number
11
Volume number
56
Pages (from-to)
6841-6853
Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

Associating a radar scatterer to a physical object is crucial for the correct interpretation of interferometric synthetic aperture radar measurements. Yet, especially for medium-resolution imagery, this is notoriously difficult and dependent on the accurate 3-D positioning of the scatterers. Here, we investigate the 3-D positioning capabilities of ENVISAT medium-resolution data. We find that the data are perturbed by range-and-epoch-dependent timing errors and calibration offsets. Calibration offsets are estimated to be about 1.58 m in azimuth and 2.84 m in range and should be added to ASAR products to improve geometric calibration. The timing errors involve a bistatic offset, atmospheric path delay, solid earth tides, and local oscillator drift. This way, we achieve an unbiased positioning capability in 2-D, while in 3-D, a scatterer was located at a distance of 28 cm from the true location. 3-D precision is now expressed as an error ellipsoid in local coordinates. Using the Bhattacharyya metric, we associate radar scatterers to real-world objects. Interpreting deformation of individual infrastructure is shown to be feasible for this type of medium-resolution data.