scholarly journals Four-Stage Inversion Algorithm for Forest Height Estimation Using Repeat Pass Polarimetric SAR Interferometry Data

2018 ◽  
Vol 10 (8) ◽  
pp. 1174 ◽  
Author(s):  
Tayebe Managhebi ◽  
Yasser Maghsoudi ◽  
Mohammad Valadan Zoej
Keyword(s):  
Extinction Coefficient ◽  
European Space Agency ◽  
Sar Interferometry ◽  
Experimental Result ◽  
Single Frequency ◽  
Height Estimation ◽  
Suggested Algorithm ◽  
Forest Height ◽  
Temporal Decorrelation ◽  
The Mean

This paper proposes a new method for forest height estimation using single-baseline single frequency polarimetric synthetic aperture radar interferometry (PolInSAR) data. The new algorithm estimates the forest height based on the random volume over the ground with a volume temporal decorrelation (RVoG+VTD) model. We approach the problem using a four-stage geometrical method without the need for any prior information. In order to decrease the number of unknown parameters in the RVoG+VTD model, the mean extinction coefficient is estimated in an independent procedure. In this respect, the suggested algorithm estimates the mean extinction coefficient as a function of a geometrical index based on the signal penetration in the volume layer. As a result, the proposed four-stage algorithm can be used for forest height estimation using the repeat pass PolInSAR data, affected by temporal decorrelation, without the need for any auxiliary data. The suggested algorithm was applied to the PolInSAR data of the European Space Agency (ESA), BioSAR 2007 campaign. For the performance analysis of the proposed approach, repeat pass experimental SAR (ESAR) L-band data, acquired over the Remningstorp test site in Southern Sweden, is employed. The experimental result shows that the four-stage method estimates the volume height with an average root mean square error (RMSE) of 2.47 m against LiDAR heights. It presents a significant improvement of forest height accuracy, i.e., 5.42 m, compared to the three-stage method result, which ignores the temporal decorrelation effect.

scholarly journals ASSESSING GROUND SUBSIDENCE PHENOMENA WITH PERSISTENT SCATTERER INTERFEROMETRY DATA IN WESTERN THESSALY, GREECE

2017 ◽  
Vol 50 (3) ◽  
pp. 1693 ◽  
Author(s):  
I. Ilia ◽  
C. Loupasakis ◽  
P. Tsangaratos
Keyword(s):  
European Space Agency ◽  
Research Area ◽  
Sar Interferometry ◽  
Ground Subsidence ◽  
Spatial And Temporal Patterns ◽  
Persistent Scatterer Interferometry ◽  
Subsidence Rate ◽  
Space Agency ◽  
Persistent Scatterer ◽  
The Mean

The main objective of the present study was to investigate ground subsidence in the wider area of Farsala, western Thessaly basin, by means of remote sensing techniques and to identify potential geo environmental mechanisms that contribute to the development of the observed surface fractures affecting the site. In this context, a set of Synthetic Aperture Radar (SAR) images, acquired in 1995-2003 by the European Space Agency (ESA) satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry (PSI) technique by the German Space Agency (DLR) during the Terrafirma project, were evaluated in order to investigate spatial and temporal patterns of deformation. Groundwater table levels of three water boreholes within the research area were processed providing the mean piezometric level drawdown and the mean annual drawdown rate. In addition, a quantitative comparison between the deformation subsidence rate and the thickness of the compressible sediments was also performed. The outcomes of the present study indicated a clear relationship in the subsidence deformation rate and the groundwater fluctuation and also a correlation between the depth of the bedrock and the deformation subsidence rate. Overall, the multitemporal SAR interferometry (DInSAR) data are proved as a valuable and suitable technique for increasing knowledge about the extent and the rate of the deformations in the current study area, proved to be affected with an increasing intensity. 

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

2019 ◽  
Vol 11 (9) ◽  
pp. 1033 ◽  
Author(s):  
Xiaofan Sun ◽  
Bingnan Wang ◽  
Maosheng Xiang ◽  
Xikai Fu ◽  
Liangjiang Zhou ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Incidence Angle ◽  
Sar Interferometry ◽  
Negative Slope ◽  
Height Estimation ◽  
Model Inversion ◽  
Time Frequency ◽  
Forest Height ◽  
Terrain Slope ◽  
Frequency Optimization

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 41 . 49 % and 11 . 96 % , respectively.

scholarly journals Improved Three Component Decomposition Technique for Forest Parameters Estimation From PolInSAR Image

2018 ◽  
Author(s):  
Tân Ngọc Nguyễn ◽  
Nghĩa Minh Phạm ◽  
Thủy Ngọc Thủy
Keyword(s):  
Electromagnetic Waves ◽  
Simulated Data ◽  
Test Site ◽  
Parameters Estimation ◽  
Tien Shan ◽  
Sar Interferometry ◽  
Single Frequency ◽  
Decomposition Technique ◽  
Forest Height ◽  
Component Decomposition

Polarimetric SAR interferometry (PolInSAR) is a hot remote sensing technique that allows to extract forest heights by means of model-based inversion. Recently, there have been plenty of research on the retrieval of vegetation parameters by single frequency single baseline PolInSAR such as the ESPRIT method, three-stage inversion. However, these methods have several shortcomings which tend to underestimate the forest height due to attenuations of the electromagnetic waves in the ground medium. In order to overcome these shortcomings, an improved three component decomposition technique using PolInSAR image is proposed in this paper. By means of coherence set and a Newton-Raphson method, the proposed method improve the accuracy of forest height estimation. The proposed algorithm performance is evaluated with simulated data from PolSARProSim software and L-band PolInSAR image pair of Tien-Shan test site is acquired by the SIR-C/X-SAR system.

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