scholarly journals MITIGATION ATMOSPHERIC EFFECTS IN INTERFEROGRAM WITH USING INTEGRATED MERIS/MODIS DATA AND A CASE STUDY OVER SOUTHERN CALIFORNIA

2018 ◽  
Vol XLII-3 ◽  
pp. 1799-1803
Author(s):  
X. Wang ◽  
P. Zhang ◽  
Z. Sun
Keyword(s):  
Water Vapor ◽  
Synthetic Aperture Radar ◽  
Atmospheric Water Vapor ◽  
Synthetic Aperture ◽  
Atmospheric Effects ◽  
Interferometric Synthetic Aperture Radar ◽  
Atmospheric Water ◽  
Resolution Imaging ◽  
Aperture Radar

Interferometric synthetic aperture radar(InSAR), as a space geodetictechnology, had been testified a high potential means of earth observation providing a method fordigital elevation model (DEM) and surface deformation monitoring of high precision. However, the accuracy of the interferometric synthetic aperture radar is mainly limited by the effects of atmospheric water vapor. In order to effectively measure topography or surface deformations by synthetic aperture radar interferometry (InSAR), it is necessary to mitigate the effects of atmospheric water vapor on the interferometric signals. This paper analyzed the atmospheric effects on the interferogram quantitatively, and described a result of estimating Precipitable Water Vapor (PWV) from the the Medium Resolution Imaging Spectrometer (MERIS), Moderate Resolution Imaging Spectroradiometer (MODIS) and the ground-based GPS, compared the MERIS/MODIS PWV with the GPS PWV. Finally, a case study for mitigating atmospheric effects in interferogramusing with using the integration of MERIS and MODIS PWV overSouthern California is given. The result showed that such integration approach benefits removing or reducing the atmospheric phase contribution from the corresponding interferogram, the integrated Zenith Path Delay Difference Maps (ZPDDM) of MERIS and MODIS helps reduce the water vapor effects efficiently, the standard deviation (STD) of interferogram is improved by 23 % after the water vapor correction than the original interferogram.

scholarly journals A Framework for Correcting Ionospheric Artifacts and Atmospheric Effects to Generate High Accuracy InSAR DEM

2020 ◽  
Vol 12 (2) ◽  
pp. 318 ◽  
Author(s):  
Zhiwei Liu ◽  
Cui Zhou ◽  
Haiqiang Fu ◽  
Jianjun Zhu ◽  
Tingying Zuo
Keyword(s):  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Atmospheric Effects ◽  
Interferometric Synthetic Aperture Radar ◽  
Dual Polarization ◽  
Digital Elevation ◽  
Split Spectrum ◽  
Dem Accuracy ◽  
Study Sites ◽  
Aperture Radar

Repeat-pass interferometric synthetic aperture radar is a well-established technology for generating digital elevation models (DEMs). However, the interferogram usually has ionospheric and atmospheric effects, which reduces the DEM accuracy. In this paper, by introducing dual-polarization interferograms, a new approach is proposed to mitigate the ionospheric and atmospheric errors of the interferometric synthetic aperture radar (InSAR) data. The proposed method consists of two parts. First, the range split-spectrum method is applied to compensate for the ionospheric artifacts. Then, a multiresolution correlation analysis between dual-polarization InSAR interferograms is employed to remove the identical atmospheric phases, since the atmospheric delay is independent of SAR polarizations. The corrected interferogram can be used for DEM extraction. Validation experiments, using the ALOS-1 PALSAR interferometric pairs covering the study areas in Hawaii and Lebanon of the U.S.A., show that the proposed method can effectively reduce the ionospheric artifacts and atmospheric effects, and improve the accuracy of the InSAR-derived DEMs by 64.9% and 31.7% for the study sites in Hawaii and Lebanon of the U.S.A., respectively, compared with traditional correction methods. In addition, the assessment of the resulting DEMs also includes comparisons with the high-precision Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) altimetry data. The results show that the selection of reference data will not affect the validation results.

scholarly journals FLOOD MAPPING USING SYNTHETIC APERTURE RADAR: A CASE STUDY OF RAMSAR FLASH FLOOD

2019 ◽  
Vol XLII-4/W16 ◽  
pp. 291-295
Author(s):  
A. Jamali ◽  
A. Abdul Rahman
Keyword(s):  
Synthetic Aperture Radar ◽  
Surface Deformation ◽  
Environmental Changes ◽  
Flash Flood ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Flooded Area ◽  
Matlab Programming ◽  
Aperture Radar

Abstract. Disasters including flash floods, earthquakes, and landslides have huge economic and social losses besides their impact on environmental disruption. Studying environmental changes due to climate change can improve public and expert sector’s awareness and response towards future disastrous events. Synthetic Aperture Radar (SAR) data and Interferometric Synthetic Aperture Radar (InSAR) technologies are valuable tools for flood modeling and surface deformation modeling. This paper proposes an efficient approach to detect the flooded area changes using Sentinel-1A over Ramsar flood on 5th October 2018. For detection of the flooded area due to flash flood SARPROZ in MATLAB programming language is used and discussed. Flooded areas in Ramsar are detected based on the change detection modeling using normalized difference values of amplitude belonging to the master image (on 28th September 2018) and the slave image (on 10th October 2018).

scholarly journals Integration PS-InSAR and MODIS PWV Data to Monitor Land Subsidence in Semarang City 2015–2018

2019 ◽  
Author(s):  
Reyhan Azeriansyah ◽  
Harintaka .
Keyword(s):  
Water Vapor ◽  
Synthetic Aperture Radar ◽  
Land Subsidence ◽  
Precipitable Water ◽  
Northern Region ◽  
Synthetic Aperture ◽  
Signal Interference ◽  
Interferometric Synthetic Aperture Radar ◽  
Entire Area ◽  
Aperture Radar

Land Subsidence is a slow on set disaster that can be found in coastal areas such as Semarang City. The cause is changing natural conditions and human activities. The observation method that is often done for this phenomenon is GNSS observation. The GNSS observations do not cover the entire area are the disadvantages of this method. Solution that can be used is to use a multi-temporal Interferometric Synthetic Aperture Radar (InSAR) method called Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR). In its application, PS-InSAR has a problem in the form of tropospheric errors that cause signal interference on SAR sensors when making acquisitions that contained in every Synthetic Aperture Radar (SAR) image. MODIS with the NIR band provide Precipitable Water Vapor (PWV) to estimate water vapor levels in the atmosphere. This component can be used in the PS-InSAR in order to eliminate the tropospheric effect on each image so that errors can be minimized and optimize the work of the PS-InSAR method. Based on the value of PS-InSAR before and after tropospheric correction, it is known that the area of Semarang City experienced a rate of land subsidence and the rate of uplift. Land subsidence rate occurs along the northern region, northeast to the east of Semarang City. Uplift rate only occurs in the southeast region due to dumping excavation activities for development and Banjir Kanal Barat due to the river revitalization process. Overall, Semarang City has experienced a land subsidence from 0 to 6.753 cm/year.

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