Evaluation of Weather Research and Forecast (WRF) microphysics schemes in simulating zenith total delay for InSAR atmospheric correction

ABSTRACT

Many researches have demonstrated the potential of Interferometric Synthetic Aperture Radar (InSAR) atmospheric correction method based on the Weather Research and Forecast (WRF) model. However, there remain some doubts about its robustness and accuracy over complex topographical areas. For meteorology, microphysics schemes play a significant role on the simulation of atmospheric parameters. But no studies have focused specifically on the impact of the microphysics schemes (MPs) on the atmospheric zenith total delay (ZTD) simulation for InSAR atmospheric correction. Therefore, we test four sophisticated MPs in WRF version 3.9.1 to simulate ZTD during the SAR signal propagation over Haiyuan in China in summer. And the ZTD values from WRF are validated by comparing to those obtained from four global position system (GPS) stations. The results show that all of the MPs can effectively reconstruct the major absolute ZTD, but regarding differential ZTD values, the Morrison double moment (M2M) and WRF Double moment 6 classes Model (WDM6) predict more accurate differential ZTD data. Moreover, WRF-based InSAR atmospheric correction utilizing the M2M obtains the most accurate deformation map results. A proper choice of MP schemes can enhance the WRF model to simulate more precise ZTD and contribute to reach a conclusion on the robustness of WRF-based InSAR atmospheric correction, especially in the complex mountain area in summer.

Acknowledgements

We are grateful to the reviewers for giving constructive comments. The NCEP GFS-FNL data are available via the NCAR Research Data Archive. The Sentinel-1A SAR images were downloaded from the European Space Agency, the GPS data used for the zenith total delay (ZTD) validation were downloaded from crustal movement observation network of China (http://www.neiscn.org/). We also thank the High-performance Computing Platform of Peking University. We used the Generic Mapping Tools (GMT) software to draw the figures and used GMTSAR to process the SAR images and complement the WRF-based atmospheric correction. We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This research was supported by the National Key Research and Development Program of China (No. 2017YFB0502703), Ministry of Science and Technology of the People’s Republic of China; and Key Project of Department of Science and Technology of Inner Mongolia Autonomous Region, China