A type of polarimetric parameter for evaluating the reliability of model-based decomposition result and its application

ABSTRACT

The reliability of the model-based decomposition result, which is seldom investigated, is a key factor in determining whether decomposition parameters can be effectively applied to polarimetric synthetic aperture radar (PolSAR) applications. In this paper, a type of polarimetric parameter for evaluating the reliability of model-based decomposition result is proposed. It originates from the degree of correlation between the scattering models. The main idea is whether the measured power can be assigned to the corresponding scattering model. The more the measured power that can be allocated to the corresponding scattering model, the more reliable the decomposition result. The C-band Radarsat-2, L-band UAVSAR, X-band TerraSAR-X, and L-band E-SAR PolSAR data are selected for experiments. The results show that the type of polarimetric parameter can effectively represent the reliability of the decomposition result. The reliabilities of surface and double-bounce scattering are high in the ocean and orthogonal buildings, respectively. For oriented buildings, the reliability of the decomposition result is lower owing to the overestimation of volume scattering. For forested areas, reliability is generally higher if volume scattering is not overestimated. Furthermore, the results show that the reliability of soil moisture retrieval is positively correlated with surface scattering reliability.

KEYWORDS:

• Model-based decomposition
• decomposition reliability
• model correlation
• soil moisture inversion
• PolSAR

Acknowledgements

The authors would like to thank the Canadian Space Agency, and German Space Agency for the image data. The authors would also like to thank the editors and anonymous reviewers for their constructive suggestions. Wentao Han implemented and developed the proposed methodology, and wrote and revised the paper. Haiqiang Fu contributed to designing the main idea, supervised the work, and revised the paper. Jianjun Zhu supervised the work, and contributed some ideas. Qinghua Xie revised the paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The Radarsat-2 data that support the findings of this study are available at [https://www.asc-csa.gc.ca/]; The UAVSAR data that support the findings of this study are available at [https://search.asf.alaska.edu/]; The TerraSAR-X data that support the findings of this study are available at [https://eoweb.dlr.de/egp/]; The E-SAR data that support the findings of this study are available at [https://earth.esa.int/eogateway/campaigns/agrisar-2006].

Additional information

Funding

This research was funded in part by the National Natural Science Foundation of China [grant numbers 41820104005, 41904004, 42030112, 42171387, and 41804004], and in part by the Fundamental Research Funds for the Central University of Central South University [grant number 2021zzts0262].