scholarly journals Extension of Ship Wake Detectability Model for Non-Linear Influences of Parameters Using Satellite Based X-Band Synthetic Aperture Radar

2019 ◽  
Vol 11 (5) ◽  
pp. 563 ◽  
Author(s):  
Björn Tings ◽  
Andrey Pleskachevsky ◽  
Domenico Velotto ◽  
Sven Jacobsen
Keyword(s):  
Synthetic Aperture Radar ◽  
Incidence Angle ◽  
Real Data ◽  
Synthetic Aperture ◽  
Ship Wake ◽  
The Past ◽  
Non Linear ◽  
Ship Wakes ◽  
Influencing Parameters ◽  
Aperture Radar

The physics of the imaging mechanism underlying the emergence of ship wakes in Synthetic Aperture Radar (SAR) images has been studied in the past by many researchers providing a well-understood theory. Therefore, many publications describe how well ship wakes are detectable on SAR under the influence of different environmental conditions like sea state or local wind, ship properties like ship speed or ship heading, and image acquisition parameters like incidence angle or satellite heading. The increased imaging capabilities of current satellite SAR missions facilitate the collection of large datasets of moving vessels. Such a large dataset of high resolution TerraSAR-X acquisitions now enables the quantitative analysis of the previously formulated theory about the detectability of ship wakes using real data. In this paper we propose an extension of our wake detectability model by using a non-linear basis which allows consideration of all the influencing parameters simultaneously. Such an approach provides new insights and a better understanding of the non-linear influence of parameters on the wake detectability and their interdependencies can now be represented. The results show that the non-linear, interdependent influence of the different influencing parameters on the detectability of wakes matches well to the oceanographic expectations published in the past. Also possible applications of the model for the extraction of missing parameters and automatic for wake detection systems are demonstrated.

scholarly journals Verification of Imaging Algorithm for Signal Processing Software within Synthetic Aperture Radar (SAR) System

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Le-tian Zeng ◽  
Chun-hui Yang ◽  
Mao-sheng Huang ◽  
Yue-long Zhao
Keyword(s):  
Signal Processing ◽  
Data Processing ◽  
Synthetic Aperture Radar ◽  
Software Testing ◽  
Real Data ◽  
Synthetic Aperture ◽  
Data Simulation ◽  
Motion Error ◽  
Processing Software ◽  
Aperture Radar

In the signal processing software testing for synthetic aperture radar (SAR), the verification for algorithms is professional and has a very high proportion. However, existing methods can only perform a degree of validation for algorithms, exerting an adverse effect on the effectiveness of the software testing. This paper proposes a procedure-based approach for algorithm validation. Firstly, it describes the processing procedures of polar format algorithm (PFA) under the motion-error circumstance, based on which it analyzes the possible questions that may exist in the actual situation. By data simulation, the SAR echoes are generated flexibly and efficiently. Then, algorithm simulation is utilized to focus on the demonstrations for the approximations adopted in the algorithm. Combined with real data processing, the bugs concealed are excavated further, implementing a comprehensive validation for PFA. Simulated experiments and real data processing validate the correctness and effectiveness of the proposed algorithm.

scholarly journals Residual Motion Error Correction with Backprojection Multisquint Algorithm for Airborne Synthetic Aperture Radar Interferometry

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2342 ◽  
Author(s):  
Pengfei Xie ◽  
Man Zhang ◽  
Lei Zhang ◽  
Guanyong Wang
Keyword(s):  
Synthetic Aperture Radar ◽  
Error Correction ◽  
Motion Compensation ◽  
Mathematical Expression ◽  
Real Data ◽  
Synthetic Aperture ◽  
Motion Error ◽  
Digital Elevation ◽  
Residual Motion ◽  
Aperture Radar

For airborne interferometric synthetic aperture radar (InSAR) data processing, it is essential to achieve precise motion compensation to obtain high-quality digital elevation models (DEMs). In this paper, a novel InSAR motion compensation method is developed, which combines the backprojection (BP) focusing and the multisquint (MSQ) technique. The algorithm is two-fold. For SAR image focusing, BP algorithm is applied to fully use the navigation information. Additionally, an explicit mathematical expression of residual motion error (RME) in the BP image is derived, which paves a way to integrating the MSQ algorithm in the azimuth spatial wavenumber domain for a refined RME correction. It is revealed that the proposed backprojection multisquint (BP-MSQ) algorithm exploits the motion error correction advantages of BP and MSQ simultaneously, which leads to significant improvements of InSAR image quality. Simulation and real data experiments are employed to illustrate the effectiveness of the proposed algorithm.

Synthetic aperture radar imaging of surface ship wakes

1988 ◽  
Vol 93 (C10) ◽  
pp. 12293 ◽  
Author(s):  
James D. Lyden ◽  
Robert R. Hammond ◽  
David R. Lyzenga ◽  
R. A. Shuchman
Keyword(s):  
Synthetic Aperture Radar ◽  
Radar Imaging ◽  
Synthetic Aperture ◽  
Surface Ship ◽  
Ship Wakes ◽  
Aperture Radar

Cross-Polarized Synthetic Aperture Radar: A New Potential Measurement Technique for Hurricanes

2012 ◽  
Vol 93 (4) ◽  
pp. 531-541 ◽  
Author(s):  
Biao Zhang ◽  
William Perrie
Keyword(s):  
Wind Speed ◽  
Synthetic Aperture Radar ◽  
Wind Direction ◽  
Incidence Angle ◽  
Microwave Radiometer ◽  
Synthetic Aperture ◽  
Cross Polarization ◽  
Potential Measurement ◽  
Wind Retrievals ◽  
Aperture Radar

We present an empirical C-band Cross-Polarization Ocean (C-2PO) model for wind retrievals from synthetic aperture radar (SAR) data collected by the RADARSAT-2 satellite. The C-2PO model relates normalized radar cross section (NRCS) in cross polarization to wind speed at 10-m height. This wind retrieval model has the characteristic that it is independent of wind direction and radar incidence angle but is quite linear with respect to wind speed. To evaluate the accuracy of the proposed model, winds with a resolution on the scale of 1 km were retrieved from a dual-polarization SAR image of Hurricane Earl on 2 September 2010, using the C-2PO model and compared with CMOD5.N, the newest available C-band geophysical model function (GMF), and validated with collocated airborne stepped-frequency microwave radiometer measurements and National Data Buoy Center data. Results suggest that for winds up to 38 m s−1, C-2PO has a bias of −0.89 m s−1 and a root-meansquare error of 3.23 m s−1 compared to CMOD5.N, which has a bias of −4.14 m s−1 and an rms difference of 6.24 m s−1. Similar results are obtained from Hurricane Ike, comparing wind retrievals from C-2PO and CMOD5.N with H*Wind data. The advantage of C-2PO over CMOD5.N and other GMFs is that it does not need any external wind direction and radar incidence angle inputs. Moreover, in the presently available quad-polarization dataset, C-2PO has the feature that the cross-polarized NRCS linearly increases even for wind speeds up to 26 m s−1 and reproduces the hurricane eye structure well, thereby providing a potential technique for hurricane observations from space.

scholarly journals Monitoring and Detecting Archaeological Features with Multi-Frequency Polarimetric Analysis

2019 ◽  
Vol 12 (1) ◽  
pp. 1 ◽  
Author(s):  
Jolanda Patruno ◽  
Magdalena Fitrzyk ◽  
Jose Manuel Delgado Blasco
Keyword(s):  
Remote Sensing ◽  
Cultural Heritage ◽  
Synthetic Aperture Radar ◽  
Incidence Angle ◽  
Small Dimension ◽  
Synthetic Aperture ◽  
Alos Palsar ◽  
Multi Temporal ◽  
L Band ◽  
Aperture Radar

In remote sensing for archaeology, an unequivocal method capable of automatic detection of archaeological features still does not exists. Applications of Synthetic Aperture Radar (SAR) remote sensing for archaeology mainly focus on high spatial resolution SAR sensors, which allow the recognition of structures of small dimension and give information of the surface topography of sites. In this study we investigated the potential of combined dual and fully polarized SAR data and performed polarimetric multi-frequency and multi-incidence angle analysis of C-band Sentinel-1, L-band Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) and of C-band Radar Satellite-2 (RADARSAT-2) datasets for the detection of surface and subsurface archaeological structures over the United Nations Educational, Scientific and Cultural Organization (UNESCO) site of Gebel Barkal (Sudan). While PALSAR offers a good historical reference, Sentinel-1 time series provide recent and systematic monitoring opportunities. RADARSAT-2 polarimetric data have been specifically acquired in 2012/2013, and have been scheduled to achieve a multi-temporal observation of the archaeological area under study. This work demonstrated how to exploit a complex but significant dataset composed of SAR full polarimetric and dual polarimetric acquisitions, with the purpose of identifying the most suitable earth observation technique for the preservation and identification of archaeological features. The scientific potential of the illustrated analysis fits perfectly with the current delicate needs of cultural heritage; such analysis demonstrates how multi-temporal and multi-data cultural heritage monitoring can be applied not only for documentation purposes, but can be addressed especially to those areas exposed to threats of different nature that require a constant and prompt intervention plans.

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