scholarly journals A Novel Method for Layover Detection in Mountainous Areas with SAR Images

2021 ◽  
Vol 13 (23) ◽  
pp. 4882
Author(s):  
Lin Wu ◽  
Hongxia Wang ◽  
Yuan Li ◽  
Zhengwei Guo ◽  
Ning Li
Keyword(s):  
Remote Sensing ◽  
Spatial Relationship ◽  
Backscatter Coefficient ◽  
Sar Images ◽  
Difference Image ◽  
Sensing Technology ◽  
Medium Resolution ◽  
Processing Difference ◽  
Initial Processing ◽  
Sar Remote Sensing

It is well known that there are geometric distortions in synthetic aperture radar (SAR) images when the terrain undulates. Layover is the most common one, which brings challenges to the application of SAR remote sensing. This study proposes a novel detection method that is mainly aimed at the layover caused by mountains and can be performed with only medium-resolution SAR images and no other auxiliary data. The detection includes the following four stages: initial processing, difference image calculation and rough and fine layover detection. Initial processing mainly obtains the potential layover areas, which are mixed with the built-up areas after classification. Additionally, according to the analysis of the backscatter coefficient (BC) of various ground objects with different polarization images, the layover areas are detected step-by-step from the mixed areas, in which the region-based FCM segmentation algorithm and spatial relationship criteria are used. Taking the Danjiangkou Reservoir area as the study area, the relevant experiments with Sentinel-1A SAR images were conducted. The quantitative analysis of detection results adopted the figure of merit (FoM), and the highest accuracy was up to 87.6% of one selected validation region. Experiments in the South Taihang area also showed the satisfactory effect of layover detection, and the values of FoM were all above 85%. These results show that the proposed method can do well in the layover detection caused by mountains. Its simplicity and effectiveness are helpful in removing the influence of layover on SAR image applications to a certain extent and improving the development of SAR remote sensing technology.

scholarly journals Air Quality Assessment over Sudan using NASA Remote Sensing Satellites Data and MERRA-2 Model

2020 ◽  
Vol 6 (3) ◽  
pp. 438-441
Author(s):  
Ibrahim Muntasir ◽  
Curci Gabriele ◽  
Habbani Farouk
Keyword(s):  
Remote Sensing ◽  
Air Quality ◽  
South Sudan ◽  
Central Africa ◽  
Ozone Monitoring Instrument ◽  
Vertical Column ◽  
The North ◽  
Sensing Technology ◽  
Medium Resolution ◽  
The Impact

Satellite remote detecting instruments have been to a great extent used to evaluate air pollutants on the ground and their impacts on human wellbeing. These instruments play an essential job by assessing emanations and air quality models yield. The study concentrated on the analysis of monthly data for the period January 2003 -December 2016 using remote sensing technology and via satellite data products for NASA's Earth navigation satellite. The tools used are Medium Resolution Imaging Spectrophotometer (MODIS), Multi-angle Imaging Spectrophotometer (MISR), the Ozone Monitoring Instrument (OMI), and the Retrospective Analysis of Modern Times for Research and Applications, Version 2 (MERRA-2). Sudan is influenced by airborne particles because of its diverse climate systems, which differ from the desert in the north to poor savanna in the center and to rich savanna in the south. The impact of air pollution is obvious during these years in Sudan. Likewise, OMI trace gas vertical column observations of nitrogen dioxide (NO2) watched higher convergences of tropospheric column NO2 in 2016 than in 2005 over Khartoum that recommends NOx emissions have increased in the city over this time period. The most elevated grouping of dust, a particulate matter (PM2.5), observed in March 2012 over Khartoum state. The highest concentration of sulfur dioxide (SO2) saw by MERRA-2 over Kuwait and South Sudan during December 2015. Noteworthy centralization concentration of black carbon observed over Iraq, Egypt, Central Africa, and South Sudan in December 2015. The most contamination from carbon monoxide watched by MERRA-2 over Iraq and north of Uganda during December 2014.

scholarly journals Change Detection in SAR Images Based on the ROF Model Semi-Implicit Denoising Method

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1179 ◽  
Author(s):  
Xuemei Lou ◽  
Zhenhong Jia ◽  
Jie Yang ◽  
Nikola Kasabov
Keyword(s):  
Remote Sensing ◽  
Principal Component ◽  
Detection Accuracy ◽  
Remote Sensing Images ◽  
Sar Images ◽  
Denoising Method ◽  
Difference Image ◽  
Time Operation ◽  
Rof Model ◽  
Difference Images

The explicit solution of the traditional ROF model in image denoising has the disadvantages of unstable results and requiring many iterations. To solve the problem, a new method, ROF model semi-implicit denoising, is proposed in this paper and applied to change detections of synthetic aperture radar (SAR) images. All remote sensing images used in this article have been calibrated by ENVI software. First, the ROF model semi-implicit denoising method is used to denoise the remote sensing images. Second, for the denoised images, difference images are obtained by the logarithmic ratio and mean ratio methods. The final difference image is obtained by principal component analysis fusion (PCA fusion) of the two difference images. Finally, the final difference image is clustered by fuzzy local information C-means clustering (FLICM) to obtain the change regions. The research results show that the proposed method has high detection accuracy and time operation efficiency.

scholarly journals APPLICATION OF VAN HENGEL AND SPITZER ALGORITHM FOR INFORMATION ON BATHYMETRY EXTRACTION USING LANDSAT DATA

2017 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Kuncoro Teguh Setiawan ◽  
Syifa Wismayati Adawiah ◽  
Takahiro OSAWA ◽  
I. Wayan Nuarsa
Keyword(s):  
Remote Sensing ◽  
Satellite Imagery ◽  
Depth Interval ◽  
Landsat Data ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Medium Resolution ◽  
Algorithm Transformation ◽  
Landsat Tm Imagery ◽  
Extract Information

Remote sensing technology provides an opportunity for effective and efficient bathymetry mapping, especially in areas which level of depth changes quickly. Bathymetry information is very useful for hydrographic and shipping safety. Landsat medium resolution satellite imagery can be used for the extraction of bathymetry information. This study aims to extract information from the Landsat bathymetry by using Van Hengel and Spitzer rotation algorithm transformation (1991) in the water of Menjangan Island, Bali. This study shows that Van Hengel and Spitzer rotation algorithm transformation (1991) can be used to extract information on the bathymetry of Menjangan Island. Extraction of bathymetric information generated from Landsat TM imagery data in March 19, 1997 had shown the depth interval of (-0.6) m to (-12.3) m and R2 value of 0.671. While Data LANDSAT ETM + dated June 23, 2000 resulted in depth interval of 0 m to (-19.1) m and R2 value of 0.796. Furthermore, data LANDSAT ETM + dated March 12, 2003 resulted in depth interval of 0 m to (-22.5) m and R2 value of 0.931.

Hyperspectral Remote Sensing Technology (HRST) program

1997 ◽  
Author(s):  
Tom Wilson ◽  
Rebecca Baugh ◽  
Ron Contillo ◽  
Tom Wilson ◽  
Rebecca Baugh ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Hyperspectral Remote Sensing ◽  
Remote Sensing Technology ◽  
Sensing Technology

Application of remote sensing methods for assessment of anthropogenic transformation of rangelands

2000 ◽  
pp. 16-25
Author(s):  
E. I. Rachkovskaya ◽  
S. S. Temirbekov ◽  
R. E. Sadvokasov
Keyword(s):  
Remote Sensing ◽  
New Technology ◽  
Field Studies ◽  
Digital Data ◽  
Aerial Images ◽  
Expert Assessment ◽  
Automated Classification ◽  
Anthropogenic Transformation ◽  
Initial Processing ◽  
Remote Sensing Methods

Capabilities of the remote sensing methods for making maps of actual and potential vegetation, and assessment of the extent of anthropogenic transformation of rangelands are presented in the paper. Study area is a large intermountain depression, which is under intensive agricultural use. Color photographs have been made by Aircraft camera Wild Heerburg RC-30 and multispectral scanner Daedalus (AMS) digital aerial data (6 bands, 3.5m resolution) have been used for analysis of distribution and assessment of the state of vegetation. Digital data were processed using specialized program ENVI 3.0. Main stages of the development of cartographic models have been described: initial processing of the aerial images and their visualization, preliminary pre-field interpretation (classification) of the images on the basis of unsupervised automated classification, field studies (geobotanical records and GPS measurements at the sites chosen at previous stage). Post-field stage had the following sub-stages: final geometric correction of the digital images, elaboration of the classification system for the main mapping subdivisions, final supervised automated classification on the basis of expert assessment. By systematizing clusters of the obtained classified image the cartographic models of the study area have been made. Application of the new technology of remote sensing allowed making qualitative and quantitative assessment of modern state of rangelands.

Application of remote sensing technology to the relation of submarine pipelines and coastal morphology

1995 ◽  
Vol 32 (2) ◽  
pp. 77-83
Author(s):  
Y. Yüksel ◽  
D. Maktav ◽  
S. Kapdasli
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Surf Zone ◽  
Hydrodynamic Forces ◽  
Construction Site ◽  
Coastal Morphology ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Sea Bed

Submarine pipelines must be designed to resist wave and current induced hydrodynamic forces especially in and near the surf zone. They are buried as protection against forces in the surf zone, however this procedure is not always feasible particularly on a movable sea bed. For this reason the characteristics of the sediment transport on the construction site of beaches should be investigated. In this investigation, the application of the remote sensing method is introduced in order to determine and observe the coastal morphology, so that submarine pipelines may be protected against undesirable seabed movement.

scholarly journals Combined Multi-Time Series SAR Imagery and InSAR Technology for Rice Identification in Cloudy Regions

2021 ◽  
Vol 11 (15) ◽  
pp. 6923
Author(s):  
Rui Zhang ◽  
Zhanzhong Tang ◽  
Dong Luo ◽  
Hongxia Luo ◽  
Shucheng You ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Identification Accuracy ◽  
Optical Remote Sensing ◽  
Sar Image ◽  
Single Time ◽  
Growing Period ◽  
Sensing Technology ◽  
Sar Imagery ◽  
Cloudy Region

The use of remote sensing technology to monitor farmland is currently the mainstream method for crop research. However, in cloudy and misty regions, the use of optical remote sensing image is limited. Synthetic aperture radar (SAR) technology has many advantages, including high resolution, multi-mode, and multi-polarization. Moreover, it can penetrate clouds and mists, can be used for all-weather and all-time Earth observation, and is sensitive to the shape of ground objects. Therefore, it is widely used in agricultural monitoring. In this study, the polarization backscattering coefficient on time-series SAR images during the rice-growing period was analyzed. The rice identification results and accuracy of InSAR technology were compared with those of three schemes (single-time-phase SAR, multi-time-phase SAR, and combination of multi-time-phase SAR and InSAR). Results show that VV and VH polarization coherence coefficients can well distinguish artificial buildings. In particular, VV polarization coherence coefficients can well distinguish rice from water and vegetation in August and September, whereas VH polarization coherence coefficients can well distinguish rice from water and vegetation in August and October. The rice identification accuracy of single-time series Sentinel-1 SAR image (78%) is lower than that of multi-time series SAR image combined with InSAR technology (81%). In this study, Guanghan City, a cloudy region, was used as the study site, and a good verification result was obtained.

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