Absolute Tropospheric Refractivity Tomography Using Multiangle Spaceborne D-InSAR

TY - JOUR

T1 - Absolute Tropospheric Refractivity Tomography Using Multiangle Spaceborne D-InSAR

AU - Li, Yuanhao

AU - Ran, Tonghua

AU - Liu, Cheng

AU - Chen, Zhiyang

AU - Ren, Junpeng

AU - Xie, Xin

AU - Wang, Yuxiao

AU - Hu, Cheng

N1 - Publisher Copyright: © 1980-2012 IEEE.

PY - 2026

Y1 - 2026

N2 - High spatial resolution 3-D tropospheric refractivity is important for the inversion of tropospheric parameters and accurate analysis of meteorological activities. Currently, spaceborne differential interferometric synthetic aperture radar (D-InSAR) is a novel tool for high spatial resolution tropospheric refractivity measurement in the absence of obvious surface deformation. However, due to the 2-D imaging constraint of synthetic aperture radar (SAR), only line-of-sight (LOS) integrated tropospheric refractivity can be captured, resulting in the loss of 3-D structure information of the troposphere. Moreover, traditional D-InSAR measurement results can only reflect the relative change of tropospheric refractivity between the two observation moments of the interferometric SAR pair. The two drawbacks limit the effectiveness of D-InSAR-inversed tropospheric products in meteorological applications. To address the issues, this article proposes a tropospheric refractivity tomography method by time-series joint processing of multiangle spaceborne D-InSAR-derived tropospheric refractivity and numerical weather prediction (NWP) data. The approach leverages simultaneous or nearly simultaneous multiangle measurements from a multisatellite SAR system or a multibeam SAR system to retrieve 3-D tropospheric refractivity, and incorporates NWP data for absolute recovery. The simulation results show the method can achieve high-accuracy 3-D absolute tropospheric refractivity, with subkilometer resolution and root mean square error (RMSE) lower than ten under different weather conditions. Using the TanDEM-X and SUPERVIEW NEO-2 constellations to verify the proposed method, the cross-validation accuracy of the retrieved tropospheric refractivity with European Centre for Medium-Range Weather Forecasts (ECMWFs), Global Forecast System (GFS), and local radiosonde is less than 13.

AB - High spatial resolution 3-D tropospheric refractivity is important for the inversion of tropospheric parameters and accurate analysis of meteorological activities. Currently, spaceborne differential interferometric synthetic aperture radar (D-InSAR) is a novel tool for high spatial resolution tropospheric refractivity measurement in the absence of obvious surface deformation. However, due to the 2-D imaging constraint of synthetic aperture radar (SAR), only line-of-sight (LOS) integrated tropospheric refractivity can be captured, resulting in the loss of 3-D structure information of the troposphere. Moreover, traditional D-InSAR measurement results can only reflect the relative change of tropospheric refractivity between the two observation moments of the interferometric SAR pair. The two drawbacks limit the effectiveness of D-InSAR-inversed tropospheric products in meteorological applications. To address the issues, this article proposes a tropospheric refractivity tomography method by time-series joint processing of multiangle spaceborne D-InSAR-derived tropospheric refractivity and numerical weather prediction (NWP) data. The approach leverages simultaneous or nearly simultaneous multiangle measurements from a multisatellite SAR system or a multibeam SAR system to retrieve 3-D tropospheric refractivity, and incorporates NWP data for absolute recovery. The simulation results show the method can achieve high-accuracy 3-D absolute tropospheric refractivity, with subkilometer resolution and root mean square error (RMSE) lower than ten under different weather conditions. Using the TanDEM-X and SUPERVIEW NEO-2 constellations to verify the proposed method, the cross-validation accuracy of the retrieved tropospheric refractivity with European Centre for Medium-Range Weather Forecasts (ECMWFs), Global Forecast System (GFS), and local radiosonde is less than 13.

KW - 3-D tropospheric refractivity

KW - differential interferometric synthetic aperture radar (D-InSAR)

KW - distributed spaceborne SAR

KW - tropospheric tomography

UR - https://www.scopus.com/pages/publications/105033640295

U2 - 10.1109/TGRS.2026.3674198

DO - 10.1109/TGRS.2026.3674198

M3 - Article

AN - SCOPUS:105033640295

SN - 0196-2892

VL - 64

JO - IEEE Transactions on Geoscience and Remote Sensing

JF - IEEE Transactions on Geoscience and Remote Sensing

M1 - 5205818

ER -