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

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

Dheenathayalan, P. (TU Delft Mathematical Geodesy and Positioning)
Small, David (University of Zürich)
Hanssen, R.F. (TU Delft Mathematical Geodesy and Positioning)

2018

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.

http://resolver.tudelft.nl/uuid:8b9689be-2c36-4aee-96c0-70fd102ca9b3

https://doi.org/10.1109/TGRS.2018.2844108

0196-2892

IEEE Transactions on Geoscience and Remote Sensing, 56 (11), 6841-6853

Institutional Repository

journal article

© 2018 P. Dheenathayalan, David Small, R.F. Hanssen