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Synthetic aperture radar (SAR) raw signal simulation is very useful for validating SAR system design parameters, for testing the effectiveness of different processing algorithms, and for other applications. If a nominal sensor rectilinear line of flight is assumed, frequency domain raw signal simulation can be used to generate the raw data with high efficiency compared with time domain simulation...
Synthetic Aperture Radar (SAR) interferometry is a well-established remote sensing technique that compares the phase of two or more complex SAR images for highly accurate measurement of displacements. Recently, the ground-based interferometric SAR (GBSAR) has proven to be a powerful tool for monitoring land deformation such as landslides, glacier movements and volcanic hazards. By using GBSAR, it...
To overcome the contradiction between wide swath and high azimuth resolution in synthetic aperture radar system, matrix inversion method is investigated to unambiguously recover the nonuniformly sampled azimuth signal. In this paper, to achieve the reconstruction filters, the system matrix is decomposed into a Vandermonde matrix and a diagonal matrix. An explicit expression of the reconstruction filters...
The high-frequency scattering of an electrically large target can be well approximated as a sum of response from individual scattering centers. The scattering center model can provide a concise and physically relevant description of the target radar signature. We use the attribute scattering center model to represent the targets' high frequency back scattering. In this model, the backscattered field...
Aiming at different types of typical false alarms, this paper proposes a hierarchical method for ship discrimination in SAR imagery. Above all, it proposes to categorize discrimination methods based on features into certain discrimination (CeD) and confidence discrimination (CoD) methods based on confidence level proposed in this paper. Each discrimination result will be marked with a confidence probability,...
Whether targets can be easily and precisely recognized is becoming a significant criterion on measuring the performance of radar. During the process of radar imaging, this criterion is always affected by the extent of sidelobe suppression. Currently, the methods of sidelobe suppression are over-studied and effective but it also owns some various shortages. In order to promote the technique of sidelobe...
Various modern SAR systems are equipped with phase array antennas and can change the squint angle during the data acquisition. With such Doppler drifts, several advanced SAR modes, like, e.g. spotlight and TOPS are possible. However, such operations cause additional problems for the interferometric processing of the data. The Doppler drift needs to be accounted for in filtering and resampling to avoid...
This paper proposed a novel method of three-dimensional (3D) imaging based on orthogonal-track ground-based arc synthetic aperture radar (GB-SAR). In the scheme, the SAR sensor moves along two orthogonal arc tracks successively and two SAR images are obtained. Then spacial information of the two dimensional (2D) SAR images are extracted to reconstruct the 3D distribution of scatterers in the common...
The interferogram of InSAR is often corrupted by noise. Therefore, the filter of the interferogram is necessary in InSAR processing. In order to overcome the drawbacks of conventional filters leading to a degradation of spatial resolution and edge blur, a novel filtering algorithm based on wavelet transform and median filter is proposed for InSAR interferogram in this paper. The key point of the proposed...
Ship detection is a key topic in remote sensing. In existing research works, SAR images are part of the data sources which have been most widely studied because they can be obtained day and night, regardless of the impact from meteorological conditions. This paper mainly aims at the existing problems of intelligent detection algorithm for ship targets in SAR image, such as the uncertainty of the automatic...
This paper introduces an extended factorized geometrical autofocus (FGA) algorithm for circular synthetic aperture radar (CSAR) which is based on the FGA in stripmap synthetic aperture radar (SAR). The strategy is that integrate the FGA with a fast factorized back-projection (FFBP) processing chain and relies on varying track parameters step by step to obtain the sharp image. The focused quality of...
Due to the complexity of synthetic aperture radar (SAR) image formation and the sensitivity to partial occlusion, automatic target recognition (ATR) remains an important, yet challenging problem in SAR image interpretation. Scattering center model provides a concise and physically relevant description of target's electromagnetic scattering phenomenon which makes it an ideal candidate for ATR. In this...
In this study, we investigated the bathymetric features of Subei Bank in the Southern Yellow Sea on ENVISAT (Environmental Satellite) ASAR (advanced synthetic aperture radar) images. There are some fingerlike features in numerous ASAR images from 2005 to 2010. Examining the detailed local bathymetry chart, we found that these features are indeed the sea surface imprints of tidal channels and sand...
For sparse Radar signals, sparse imaging method is subversion of the traditional imaging method, which breaks through the limitations existing in traditional imaging method. In order to improve the imaging quality of Radar signals, we don't only realize the sparse radar imaging algorithm, but also propose a new method for choosing regularization parameter in 2D radar imaging. The imaging result verifies...
Downward looking sparse linear array three-dimensional synthetic aperture radar (DLSLA 3-D SAR) can obtain the 3-D image of the true scene, and compressive sensing (CS) provide the solution for cross-track super-resolution reconstruction. This paper concerns the issue of optimizing the measurement matrix, which affects the reconstruction performance. Two mutual coherence based criteria are proposed...
Multibaseline SAR tomography is an advanced 3D SAR imaging mode, which is widely utilized in many military and civilian fields. As the height data received by tomography SAR is sparse and non uniform, conventional method can not obtain satisfactory imaging results. The compressed sensing (CS) based methods for tomography SAR imaging perform well in the case of large number of baselines. However, the...
SAR image despeckling is a fundamental problem which degrades the performances of SAR image automated analysis and information extraction. In this paper, we proposed an SAR image despeckling algorithm by iterative non-local low-rank constraint. Dual weights are used to make the best use of the non-local similarity relation. Logarithmic transform is firstly applied to gain independent variance noise...
The interaction of electromagnetic wave and ground vegetation is very complex, so it's necessary to build a coherent scattering model to calculate the field distribution of vegetation. Coherent scattering model was developed based on distorted Born approximation (DBA) which can be obtained from volume integral equations with half-space dyadic Green Functions. In this paper, we combine a 3-D coherent...
Theoretical analysis of the time domain synthetic bandwidth method applied in synthetic aperture radar (SAR) is formulated in this paper firstly. Some problem arising in practical implementation of the method in inverse synthetic aperture radar (ISAR) direct intermediate frequency sampling (DIFS) mode is discussed. The solution to the problem is proposed in this paper. First of all, the transmitted...
Hazards due to ground movements and instability in man-made structures can lead to considerable human and economic losses. The decrease of permafrost areas, changes in precipitation patterns and increase of extreme weather which due to the recent climate change is actually influencing the weather-related mass movement activities. In Malaysia, landslide is the most commonly seen land deformation issue...
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