scholarly journals An Integrated Approach for Mapping Three-Dimensional CoSeismic Displacement Fields from Sentinel-1 TOPS Data Based on DInSAR, POT, MAI and BOI Techniques: Application to the 2021 Mw 7.4 Maduo Earthquake

2021 ◽  
Vol 13 (23) ◽  
pp. 4847
Author(s):  
Lang Xu ◽  
Qiang Chen ◽  
Jing-Jing Zhao ◽  
Xian-Wen Liu ◽  
Qian Xu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Integrated Approach ◽  
Satellite System ◽  
Displacement Fields ◽  
Fusion Algorithm ◽  
High Quality ◽  
Integrated Method ◽  
Global Navigation Satellite ◽  
Interferometric Sar ◽  
Mean Square Errors

Sentinel-1 Terrain Observation by Progressive Scans (TOPS) data have been widely applied in earthquake studies due to their open-source policy, short revisit cycle and wide coverage. However, significant near-fault displacement gradients and the moderate azimuth resolution of TOPS data make achieving high-precision along-track measurements challenging, which prevents the generation of high-quality three-dimensional (3D) displacement maps. Here, we propose an integrated method to retrieve high-quality 3D displacements based on the differential interferometric SAR (DInSAR), burst-overlap interferometry (BOI), multiple-aperture InSAR (MAI) and pixel offset tracking (POT) techniques, which are achieved to use only two track Sentinel-1 TOPS data with different viewing geometries. The key step of this method is using a weighted fusion algorithm with the interpolated BOI-derived and MAI-derived 3D displacements. In a case study of the 2021 Maduo earthquake, the calculated root mean square errors (RMSEs) from global navigation satellite system (GNSS) data and the InSAR-derived 3D displacement fields were found to be 6.3, 5.8 and 1.7 cm in north–south, east–west and up–down components, respectively. Moreover, the slip model of the 2021 Maduo earthquake jointly estimated by DInSAR and BOI measurements indicates that this seismic event was dominated by sinistral strike-slip motion mixed with some dip-slip movements; the estimated seismic moment was 1.75 × 1020 Nm, corresponding to a Mw 7.44 event.

scholarly journals Charcoal heaps volume estimation based on unmanned aerial vehicles.

2021 ◽  
Author(s):  
Luiza Marina Esteves de Carvalho ◽  
Alessandra Melo ◽  
Glauco José de Matos Umbelino ◽  
Jan-Peter Mund ◽  
Jhonathan Gomes dos Santos ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Satellite System ◽  
Volume Estimation ◽  
Survey Method ◽  
High Quality ◽  
Monitoring Method ◽  
Geometric Precision ◽  
Topographic Survey ◽  
Uav Images ◽  
Global Navigation Satellite

Abstract The charcoal stock in a forest company is controlled based on the theoretical capacity of the masonry ovens (input) and shipped trucks (output). During the year, the company must monitor the stock for the purposes of accountability reports. This study proposes a more efficient and equally precise survey method that overcomes the challenges of the common monitoring system in Brazil. During this study, a new monitoring method based on digital stereoscopy from UAV images was developed, implemented and evaluated. The results were compared with a traditional topographic survey. A masonry oven's complex containing eight charcoal heaps was flown and surveyed using a multi-engine UAV, with an integrated Global Navigation Satellite System (GNSS) and RTK equipment. Two stereoscopic processing methods were applied: (1) very low quality and (2) high quality to image alignment, reconstruction of the dense cloud, face count and in three-dimensional mesh creation. Low quality products showed geometric deformities when compared to high quality, but resulted in similar estimation to the topographic survey. The results indicated that the charcoal heaps' volume estimation using UAV derived orthomosaics can replace the conventional method of GNSS RTK surveys with considerable gains in stockpile volume accuracy, inventory frequency, and safety. In the case of high accuracy parameterization, improvements in geometric precision and accuracy are also produced.

scholarly journals An Efficient PET-MRI Medical Image Fusion based on IHS-NSCT-PCA Integrated Method

2019 ◽  
Vol 9 (2) ◽  
pp. 2073-2079
Keyword(s):  
Structural Data ◽  
Fusion Rule ◽  
Integrated Approach ◽  
Disease Diagnosis ◽  
Weighted Averaging ◽  
Fusion Algorithm ◽  
Integrated Method ◽  
Histogram Matching ◽  
Multiple Imaging ◽  
Fused Image

Merging of multiple imaging modalities leads to a single image that acquire high information content. These find useful applications in disease diagnosis and treatment planning. IHS-PCA method is a spatial domain approach for fusion that offersfinestvisibility but demands vast memory and it lacks steering information. We propose an integrated approach that incorporates NSCT combined with PCA utilizing IHS space and histogram matching. The fusion algorithm is applied on MRI with PET image and improved functional property was obtained. The IHS transform is a sharpening technique that converts multispectral image from RGB channels to Intensity Hue and Saturation independent values. Histogram matching is performed with intensity values of the two input images. Pathological details in images can be emphasized in multi-scale and multi-directions by using PCA withNSCT. Fusion rule applied is weighted averaging andprincipal components are used for dimensionality reduction. Inverse NSCT and Inverse IHS are performed so as to obtain the fused image in new RGB space. Visual and subjective investigation is compared with existing methods which demonstrate that our proposed technique gives high structural data content with high spatial and spectral resolution compared withearlier methods.

Ocean Navigation Method Based on Multi-System and Multi-Source Data Fusion

2020 ◽  
pp. 1-16
Author(s):  
Xiang Wang ◽  
Jingxian Liu ◽  
Zhao Liu
Keyword(s):  
Data Fusion ◽  
Satellite System ◽  
Single Frequency ◽  
Fusion Algorithm ◽  
Ship Maneuvering ◽  
Source Data ◽  
Huge Impact ◽  
Potential Risks ◽  
Global Navigation Satellite ◽  
Navigation Method

Ship navigation requires accurate positioning, navigation and timing (PNT) data. PNT data from a single source has uncertainties and potential risks. Wrong PNT data has a huge impact on ship maneuvering, and at the same time, it may cause huge losses to national assets and national security. This chapter proposes a data fusion algorithm based on single-frequency global navigation satellite system (GNSS) and inertial navigation system (INS) to obtain PNT data, which can improve the availability, accuracy, reliability, continuity, and robustness. The experimental results show that the data fusion method combining median filtering and Kalman filtering can improve the system's ability to acquire PNT data. When blocking GNSS acquisition of PNT data, relying on INS, you can still obtain PNT data, which can make up for the ability to obtain PNT data from GNSS.

scholarly journals Rigorous Boresight Self-Calibration of Mobile and UAV LiDAR Scanning Systems by Strip Adjustment

2019 ◽  
Vol 11 (4) ◽  
pp. 442 ◽  
Author(s):  
Zhen Li ◽  
Junxiang Tan ◽  
Hua Liu
Keyword(s):  
Inertial Measurement Unit ◽  
Point Clouds ◽  
Calibration Method ◽  
Satellite System ◽  
Measurement Unit ◽  
Inertial Measurement ◽  
Self Calibration ◽  
Global Navigation Satellite ◽  
Mean Square Errors ◽  
Scanning Systems

Mobile LiDAR Scanning (MLS) systems and UAV LiDAR Scanning (ULS) systems equipped with precise Global Navigation Satellite System (GNSS)/Inertial Measurement Unit (IMU) positioning units and LiDAR sensors are used at an increasing rate for the acquisition of high density and high accuracy point clouds because of their safety and efficiency. Without careful calibration of the boresight angles of the MLS systems and ULS systems, the accuracy of data acquired would degrade severely. This paper proposes an automatic boresight self-calibration method for the MLS systems and ULS systems using acquired multi-strip point clouds. The boresight angles of MLS systems and ULS systems are expressed in the direct geo-referencing equation and corrected by minimizing the misalignments between points scanned from different directions and different strips. Two datasets scanned by MLS systems and two datasets scanned by ULS systems were used to verify the proposed boresight calibration method. The experimental results show that the root mean square errors (RMSE) of misalignments between point correspondences of the four datasets after boresight calibration are 2.1 cm, 3.4 cm, 5.4 cm, and 6.1 cm, respectively, which are reduced by 59.6%, 75.4%, 78.0%, and 94.8% compared with those before boresight calibration.

scholarly journals A Joint Method Based on Time-Frequency Distribution to Detect Time-Varying Interferences for GNSS Receivers with a Single Antenna

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1946 ◽  
Author(s):  
Qingshui Lv ◽  
Honglei Qin
Keyword(s):  
Hough Transform ◽  
Frequency Estimation ◽  
Satellite System ◽  
Time Varying ◽  
Actual Performance ◽  
Time Frequency ◽  
Single Antenna ◽  
Global Navigation Satellite ◽  
Mean Square Errors ◽  
Joint Method

In this paper, a joint method combining Hough transform and reassigned smoothed pseudo Wigner-Ville distribution (RSPWVD) is presented to detect time-varying interferences with crossed frequency for a Global Navigation Satellite System (GNSS) receiver with a single antenna. The proposed method can prevent the cross-term interference and detect the time-varying interferences with crossed frequency which cannot be achieved by the classical time-frequency (TF) analysis with the peak detection method. The actual performance of the developed method has been evaluated by experiments with conditions where the real BeiDou system (BDS) B1I signals are corrupted by the simulated chirp interferences. The results of experiments show that the introduced method is effectively able to detect chirp interferences with crossed frequency and provide the same root mean square errors (RMSE) of the parameter estimation for chirp one and the improved initial frequency estimation for chirp two compared with the Hough transform of Wigner-Ville distribution (WVD) when the jamming to noise ratio (JNR) equals or surpasses 4 dB.

scholarly journals EGNOS Based APV Procedures Development Possibilities In The South-Eastern Part Of Poland

2014 ◽  
Vol 21 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Wojciech Z. Kaleta
Keyword(s):  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Satellite System ◽  
Civil Aviation ◽  
The South ◽  
South Eastern ◽  
System Integrity ◽  
New Instrument ◽  
Global Navigation Satellite ◽  
First Time

AbstractOn 14th and 15th March 2011 for the first time approach with vertical guidance (APV-I) was conducted on Polish territory in Katowice, Kraków and Mielec. This was the milestone for GNSS (Global Navigation Satellite System) and Area Navigation (RNAV) use as a new instrument approach chance for NPA (Non-Precision Approach) and PA (Precision Approach) in Poland. The paper presents the experiment study of EGNOS SIS (Signal in Space) due to APV (Approach with Vertical Guidance) procedures development possibilities in the south-eastern part of Poland. Researches were conducted from January 2014 till June 2014 in three Polish cities: Warszawa, Kraków and Rzeszów. EGNOS as SBAS (Satellite Based Augmentation System) in according with ICAO's Annex 10 has to meet restrictive requirements for three dimensional accuracy, system integrity, availability and continuity of SIS. Because of ECAC (European Civil Aviation Conference) states to EGNOS coverage in the eastern part of Europe, location of mention above stations, shows real usefulness for SIS tests and evaluation of the results [EUROCONTROL, 2008].

scholarly journals Algorithm for Generating 3D Geometric Representation Based on Indoor Point Cloud Data

2020 ◽  
Vol 10 (22) ◽  
pp. 8073
Author(s):  
Min Woo Ryu ◽  
Sang Min Oh ◽  
Min Ju Kim ◽  
Hun Hee Cho ◽  
Chang Baek Son ◽  
...  
Keyword(s):  
Point Cloud ◽  
Indoor Environment ◽  
Three Dimensional ◽  
Satellite System ◽  
Normal Vector ◽  
Geometric Representation ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Data Process ◽  
Global Navigation Satellite

This study proposes a new method to generate a three-dimensional (3D) geometric representation of an indoor environment by refining and processing an indoor point cloud data (PCD) captured through backpack laser scanners. The proposed algorithm comprises two parts to generate the 3D geometric representation: data refinement and data processing. In the refinement section, the inputted indoor PCD are roughly segmented by applying random sample consensus (RANSAC) to raw data based on an estimated normal vector. Next, the 3D geometric representation is generated by calculating and separating tangent points on segmented PCD. This study proposes a robust algorithm that utilizes the topological feature of the indoor PCD created by a hierarchical data process. The algorithm minimizes the size and the uncertainty of raw PCD caused by the absence of a global navigation satellite system and equipment errors. The result of this study shows that the indoor environment can be converted into 3D geometric representation by applying the proposed algorithm to the indoor PCD.

scholarly journals Fast four-dimensional tensile test monitored via X-ray computed tomography: Elastoplastic identification from radiographs

2019 ◽  
Vol 54 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Clément Jailin ◽  
Ante Buljac ◽  
Amine Bouterf ◽  
François Hild ◽  
Stéphane Roux
Keyword(s):  
Tensile Test ◽  
Correlation Method ◽  
Integrated Approach ◽  
Companion Paper ◽  
Constitutive Law ◽  
Free Form ◽  
Model Parameters ◽  
Displacement Fields ◽  
Integrated Method ◽  
Ductile Behavior

A projection-based digital volume correlation method (presented in a companion paper) is extended to an integrated approach for the calibration of an elastoplastic law based on a single radiograph per loading step. Instead of following a two-step sequential procedure (i.e. first, measurement of the displacement field; second, identification), the integrated method aims at identifying few model parameters directly from the gray-level projections. The analysis of an in situ tensile test composed of 127 loading steps performed in 6 min is presented. An isotropic elastoplastic constitutive law with free-form hardening behavior (i.e. controlled by only eight parameters) is identified and shows a ductile behavior (up to 6.3% strain before failure). A large improvement on the residual quality is shown and validates the proposed model and procedure. The obtained displacement fields are similar to those measured with no mechanical integration. A different parameterization of the constitutive law provides a very close result, thereby assessing the robustness of the procedure.

An Integrated Approach to Optimal Three Dimensional Layout and Routing

1998 ◽  
Vol 120 (3) ◽  
pp. 510-512 ◽  
Author(s):  
S. Szykman ◽  
J. Cagan ◽  
P. Weisser
Keyword(s):  
Simulated Annealing ◽  
Three Dimensional ◽  
Integrated Approach ◽  
Substantial Improvement ◽  
Routing Algorithms ◽  
Future Research ◽  
Test Case ◽  
Integrated Method ◽  
Route Design ◽  
Product Layout

This paper integrates simulated annealing-based component packing, layout and routing algorithms into a concurrent approach to product layout optimization. The design of a heat pump is presented to compare the integrated method to the previous sequential layout-then-route approach; results show a substantial improvement in route design with more organized component placements. The example is given in detail to provide a test case for future research in this area.

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