scholarly journals The Extraction of Ocean Tidal Loading from ASAR Differential Interferograms

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 632 ◽  
Author(s):  
Wei Peng ◽  
Qijie Wang ◽  
Yunmeng Cao
Keyword(s):  
Synthetic Aperture Radar ◽  
The United States ◽  
Synthetic Aperture ◽  
Tectonic Deformation ◽  
Spatial Characteristics ◽  
Tide Model ◽  
Ocean Tidal Loading ◽  
Tidal Loading ◽  
Mean Square Errors ◽  
Aperture Radar

The spatiotemporal crustal non-tectonic deformation caused by ocean tidal loading (OTL) can reach the centimeters scale in coastal land areas. The temporal variation of the site OTL displacements can be estimated by the global positioning system (GPS) technique, but its spatial variation needs to be further determined. In this paper, in order to analyze the spatial characteristics of the OTL displacements, we propose a multi-scale decomposition method based on signal spatial characteristics to derive the OTL displacements from differential interferometric synthetic aperture radar (D-InSAR) measurements. The method was tested using long-term advanced synthetic aperture radar (ASAR) data and GPS reference site data from the Los Angeles Basin in the United States, and we compared the results with the FES2014b tide model. The experimental results showed that the spatial function of the OTL displacements in an ASAR image can be represented as a higher-order polynomial function, and the spatial trends of the OTL displacements determined by the InSAR and the GPS techniques are basically consistent with the FES2014b tide model. The root-mean-square errors of the differences between the spatial OTL displacements of these two methods and the FES2014b tide model are less than 0.8 mm. The results indicate that the OTL displacement extracted from InSAR data can accurately reflect the spatial characteristics of the OTL effect, which will help to improve the spatial resolution and accuracy of the OTL displacement in coastal areas.

scholarly journals Two-Dimensional Ship Velocity Estimation Based on KOMPSAT-5 Synthetic Aperture Radar Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1474 ◽  
Author(s):  
Minyoung Back ◽  
Donghan Kim ◽  
Sang-Wan Kim ◽  
Joong-Sun Won
Keyword(s):  
Synthetic Aperture Radar ◽  
Estimation Method ◽  
Velocity Estimation ◽  
Synthetic Aperture ◽  
Minimum Size ◽  
Estimation Accuracy ◽  
Two Dimensional ◽  
Synthetic Aperture Radar Data ◽  
Mean Square Errors ◽  
Aperture Radar

Continuously accumulating information on vessels and their activities in coastal areas of interest is important for maintaining sustainable fisheries resources and coastal ecosystems. The speed, heading, sizes, and activities of vessels in certain seasons and at certain times of day are useful information for sustainable coastal management. This paper presents a two-dimensional vessel velocity estimation method using the KOMPSAT-5 (K5) X-band synthetic aperture radar (SAR) system and Doppler parameter estimation. The estimation accuracy was evaluated by two field campaigns in 2017 and 2018. The minimum size of the vessel and signal-to-clutter ratio (SCR) for optimum estimation were determined to be 20 m and 7.7 dB, respectively. The squared correlation coefficient R2 for vessel speed and heading angle were 0.89 and 0.97, respectively, and the root-mean-square errors of the speed and heading were 1.09 m/s (2.1 knots) and 17.9°, respectively, based on 19 vessels that satisfied the criteria of minimum size of vessel and SCR. Because the K5 SAR is capable of observing a selected coastal region every day by utilizing various modes, it is feasible to accumulate a large quantity of vessel data for coastal sea for eventual use in building a coastal traffic model.

scholarly journals Detection and measurement of land subsidence and uplift using interferometric synthetic aperture radar, San Diego, California, USA, 2016–2018

2020 ◽  
Vol 382 ◽  
pp. 45-49
Author(s):  
Justin T. Brandt ◽  
Michelle Sneed ◽  
Wesley R. Danskin
Keyword(s):  
Synthetic Aperture Radar ◽  
Land Subsidence ◽  
Land Surface ◽  
San Diego ◽  
The United States ◽  
Synthetic Aperture ◽  
United States Geological Survey ◽  
Interferometric Synthetic Aperture Radar ◽  
Groundwater Levels ◽  
Aperture Radar

Abstract. Land subsidence associated with groundwater-level declines is stipulated as an “undesirable effect” in California's Sustainable Groundwater Management Act (SGMA), and has been identified as a potential issue in San Diego, California, USA. The United States Geological Survey (USGS), the Sweetwater Authority, and the City of San Diego, undertook a cooperative study to better understand the hydromechanical response of the coastal aquifer system using Interferometric Synthetic Aperture Radar (InSAR) techniques. Three periods of interest were analyzed for this study that correspond to the periods before and after two substantial changes were made to the location and volume of pumpage: (1) April–August 2016 when groundwater levels and land surface elevation were relatively stable during normal pumping, (2) September 2016–May 2017 when groundwater levels recovered and the land surface uplifted during a period of substantially reduced pumping, (3) June 2017–October 2018 when groundwater levels declined and land subsidence occurred when pumpage resumed and expanded to new wells. Spatial and temporal characterization of the hydromechanical response to changes in pumpage is important for managing land subsidence. Further study using InSAR techniques, especially when combined with ground-based geodetic and monitoring-well networks, will provide water managers information to help effectively manage groundwater resources as stipulated in the SGMA.

scholarly journals Ground Deformation Analysis Using InSAR and Backpropagation Prediction with Influencing Factors in Erhai Region, China

2019 ◽  
Vol 11 (10) ◽  
pp. 2853 ◽  
Author(s):  
Yuyi Wang ◽  
Yahui Guo ◽  
Shunqiang Hu ◽  
Yong Li ◽  
Jingzhe Wang ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Water Level ◽  
Influencing Factors ◽  
Ground Deformation ◽  
Synthetic Aperture ◽  
Continuous Increase ◽  
Building Area ◽  
Mean Square Errors ◽  
Cumulative Precipitation ◽  
Aperture Radar

The long continuity of Interferometric Synthetic Aperture Radar (InSAR) can provide high space and resolution data for ground deformation investigations. The ground deformation in this paper appeared in the city’s development, although it is close to the Erhai region, which is different from a water-deficient city. Therefore, the analysis and prediction of ground deformation using a new method is required. In this study, Sentinel-1 Synthetic Aperture Radar (SAR) images from 2015 to 2018 were used to study the characteristics of ground deformation in the Erhai region using the Small Baseline Subset Interferometric SAR (SBAS-InSAR) technique. The results were cross-validated using ascending and descending direction images to ensure the accuracy. In addition, the results showed that there was little ground deformation in the northern part of the Erhai region, while there was obvious ground deformation in the southern part. Four influencing factors—including the building area, water level, cumulative precipitation, and cumulative temperature of the southern Erhai region—were used together to predict the cumulative ground deformation using back-propagation (BP). The R of all the involved data was 0.966, and the root mean square errors (RMSEs) between the simulated values using BP and the true measured values were 3.063, 1.003, and 1.119, respectively. The results showed that BP has great potential in predicting the change tendency of ground deformation with high precision. The main reason for ground deformation is the continuous increase of building area; the water level followed. The cumulative precipitation and cumulative temperature are the reasons for the seasonal ground deformation. Some countermeasures and suggestions are given to face the challenge of serious ground deformation.

Sign in / Sign up

Export Citation Format

Share Document