S-RVoG Model Inversion Based on Time-Frequency Optimization for P-Band Polarimetric SAR Interferometry

• Published in: Remote Sensing
• Main Authors: Xiaofan Sun, Bingnan Wang, Maosheng Xiang, Xikai Fu, Liangjiang Zhou, Yinwei Li
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: P-band Pol-InSAR; RVoG model; S-RVoG model; time-frequency optimization; single-baseline; terrain slope; Science; Q; Northern Sweden
• Online Access: https://doi.org/10.3390/rs11091033; https://doaj.org/article/a7dda4e45c4542029e7edb68db45c792

This paper investigates the potential of the time-frequency optimization on the basis of the sublook decomposition for forest height estimation. The optimization is deemed to be capable of extracting a relatively accurate volume contribution when P-band polarimetric interferometric synthetic aperture radar (Pol-InSAR) systems are adopted to observe forest-covered areas. The highest and the lowest phase centers acquired by the time-frequency optimization modify the conventional three-stage inversion process. This paper presents, for the first time, a performance assessment of the time-frequency optimization on P-band Pol-InSAR data over boreal forests. Simultaneously, to alleviate the model inversion errors caused by topographic fluctuations, forest height is estimated based on the sloped Random Volume over Ground (S-RVoG) model in which the incidence angle is corrected with the terrain slope. The E-SAR P-band Pol-InSAR data acquired during the BIOSAR 2008 campaign in Northern Sweden is utilized to evaluate the performance of the proposed method. From the results of the forest height estimation preprocessed with time-frequency optimization, the root mean square error (RMSE) of Random Volume over Ground (RVoG) and S-RVoG model on negative slope are 5.09 m and 4.71 m, respectively. It is concluded that the time-frequency processing and negative terrain slope compensation improve the inversion performance by <math display="inline"> <semantics> <mrow> <mn>41</mn> <mo>.</mo> <mn>49</mn> <mo>%</mo> </mrow> </semantics> </math> and <math display="inline"> <semantics> <mrow> <mn>11</mn> <mo>.</mo> <mn>96</mn> <mo>%</mo> </mrow> </semantics> </math> , respectively.