SyntheticAperture Radar (SAR) has the ability to work inevery hour, under all weather conditions. The multichannel SAR well solved the dilemma between the swathcoverage and the azimuth resolution. However in reality, ...
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ISBN:
(纸本)9781785610387
SyntheticAperture Radar (SAR) has the ability to work inevery hour, under all weather conditions. The multichannel SAR well solved the dilemma between the swathcoverage and the azimuth resolution. However in reality, the phase equalization of each sub-channel is influencedby many unideal factors, which can degrade the imagequality. In this paper, firstly the main factors are summarized and their effects are calculated. Then the interferometric phasemethod is introduced to compensate the phase error. Finally we applied the following methods of error estimation and compensation in the channel uncertainty simulation and get a good imagining result.
In this paper, we combine the monogenic signal with the histogram of oriented gradient (HOG) feature, and propose a new low-level feature: Monogenic-HOG (MG-HOG);then use the bag of words (BoW) model to construct the ...
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Automatic target recognition (ATR) in synthetic aperture radar (SAR) images plays an important role. An important step in SAR target recognition is to transform the raw data to a feature space with the property of wit...
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Geosynchronous SAR (GEO SAR) is susceptible to ionosphere due to the ultra-long integration time and ultrawide coverage, resulting in image defocusing and image drift. This paper demonstrates a validation experiment o...
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ISBN:
(纸本)9781849199940
Geosynchronous SAR (GEO SAR) is susceptible to ionosphere due to the ultra-long integration time and ultrawide coverage, resulting in image defocusing and image drift. This paper demonstrates a validation experiment of analysing ionospheric impacts on GEO SAR focusing. The validation experiment consists of data acquisition of the global navigation satellites system (GNSS) satellites signals (including GPS and Beidou IGSO satellites), equivalent pre-processing, GEO SAR signal modelling, image focusing and evaluating. The recorded data are equivalently transformed into the space and time frame of GEO SAR. Then the phase errors induced by ionosphere in GEO SAR can be generated from the equivalently preprocessed data and then incorporated into the GEO SAR signals. The following image focusing and the impacts analysis are accomplished. In cases of the current GEO SAR system configuration, the existence of ionosphere will induce image drifts but can be corrected through image registration techniques. In other aspects, the image can be well focused in range direction. But for the azimuthal focusing, the second and higher derivatives of TEC will result in defocusing and the thresholds of wellfocusing are dependent on the specific GEO SAR system configuration.
The fast and steady feature extraction and key point matching are key factors to SAR (synthetic aperture radar) image automatic registration algorithm. The real-timeprocessing of the algorithm in SAR is one of the ch...
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ISBN:
(纸本)9781849199940
The fast and steady feature extraction and key point matching are key factors to SAR (synthetic aperture radar) image automatic registration algorithm. The real-timeprocessing of the algorithm in SAR is one of the challenges that need to be solved urgently. This paper aims at improving the efficiency of the description of key point in SIFT algorithm. We implemented the rapid calculation of the feature extraction section in SIFT (scale invariant feature transform) based on embedded NVIDIA GPU-Tegra K1 by fully taking the advantages of multi-cores of GPU in parallel computing, floating point calculation, memory management, etc. And the speed ratio of the accelerated calculation of the SIFT feature reaches 5.5.
Due to the influence of air currents and the control of the platform's own power system, acceleration is often present in the motion platform equipped with synthetic aperture radar (SAR) system, which causes the a...
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This paper presents an original urban detection on remote sensing images, which is based on efficient textural features extracted from contourlet transform domain. Since cities and towns are consisted of various objec...
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ISBN:
(纸本)9781849199940
This paper presents an original urban detection on remote sensing images, which is based on efficient textural features extracted from contourlet transform domain. Since cities and towns are consisted of various objects, which have great differences in scale, directivity and texture characteristics, it is adaptive for contourlet transform to detecting urbans result from its discrete-domain multi-resolution and multi-direction expansion using nonseparable filter banks. Therefore, construction of contourlet coefficients can capture the intrinsic geometrical structure that is the key in visual information. On the other hand, we employ robust texture features in contourlet domain for recognizing urban regions from other land type by LS-SVM classifier. The performance of the proposed approach was validated by experiments carried on a data set of large images consisting of heavily negative samples.
Cloud detection plays a significant role in remote sensing (RS) image processing. Numbers of cloud detection algorithms have been developed in the literature. However, they suffer the weakness of omitting thin and sma...
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Wideband distributed coherent aperture radar has become the most significant direction in next generation radar. Its high range resolution due to wideband and high angle resolution because of distributed aperture can ...
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ISBN:
(纸本)9781785610387
Wideband distributed coherent aperture radar has become the most significant direction in next generation radar. Its high range resolution due to wideband and high angle resolution because of distributed aperture can accurately estimate the target's range and angle. In result, tracking and identification can be employed. However, single radar cannot detect the long-range target because of its relatively low SNR. Therefore, precisely estimating the coherent parameters under low SNR in order to achieve the coherent synthesize is the key problem in distributed coherent aperture radar. In this paper, the wideband dechirping echo and coherent parameters model are built firstly. Then a novel coherent parameters estimation method based on MUSIC and Kalman filter is proposed. Finally, simulations are carried out to illustrate the performance of the proposed method under low SNR.
In order to classify the remote sensing land-use objects efficiently with the very high resolution (VHR) remote sensing images, this letter proposes a remote sensing object classification method based on bag of visual...
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ISBN:
(纸本)9781849199940
In order to classify the remote sensing land-use objects efficiently with the very high resolution (VHR) remote sensing images, this letter proposes a remote sensing object classification method based on bag of visual words (BOV) model. This method combines the scale invariant feature transform (SIFT) feature and the texture feature as remote sensing words. Then, the remote sensing words are used for generating word frequency histograms. The histogram is the bridge of the remote sensing words and the classifier. At last, in the classifier design section, the histogram intersection kernel (HIK) is adopted in the SVM. We use the proposed classification method to classify the UC Merced dataset and self-made dataset. Experimental results show that the proposed remote sensing object classification method yields better classification than the existing methods in terms of the classification accuracy.
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