This paper concentrates on the hardware implementation of CORDIC algorithm for computing inverse trigonometric functions like arcsine and arccosine. We improve the existing algorithm by changing the initial rotating v...
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ISBN:
(纸本)9781849199940
This paper concentrates on the hardware implementation of CORDIC algorithm for computing inverse trigonometric functions like arcsine and arccosine. We improve the existing algorithm by changing the initial rotating vector of the iterations and modifying the judging condition of rotation direction. Due to the improvement, two iterations are saved and the drawback of the previous algorithm is corrected. In contrasting with the previous implementation, the improved algorithm consumes less hardware resources and its computing results are more accuracy.
Since network server based on traditional network modal has the characteristics of high CPU utilization, long time to response client connections, low data transmission speed and the lack of common multithreading, I/O...
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Since network server based on traditional network modal has the characteristics of high CPU utilization, long time to response client connections, low data transmission speed and the lack of common multithreading, I/O Completion Port, namely IOCP, was proposed to implement the large-scale network server. Firstly, the basic procedure of building the network server was provided, then several common problems was discussed deeply and the corresponding solutions was given, at last, the performance of the server based on IOCP mechanism was compared with the performance of the server based on overlapped I/O mechanism. The experimental results show that IOCP mechanism has good technical advantages in the process of designing large-scale network communication system.
With the rapid development of satellite-based signal processing technologies comes the widespread deployment of SAR image processing systems in spaceborne applications, many of which are implemented as FPGA-based syst...
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ISBN:
(纸本)9781849199940
With the rapid development of satellite-based signal processing technologies comes the widespread deployment of SAR image processing systems in spaceborne applications, many of which are implemented as FPGA-based systems thanks to the introduction of modern programmable devices with high capacity and complexity. However, as raw data of SAR satellites grow in size and bandwidth the effective implementation and especially the efficient system verification are emerging as the bottleneck in the development of FPGA-based SAR image processing systems. This paper proposes methods in the verification phase of FPGA-based SAR processing system development which on one hand increases the verification speed during simulations and on the other addresses the hardware/Matlab mismatch issue through comparison of floating point numbers on grounds of error analysis from a mathematical approach. Actual development process indicate that the proposed methods guarantee quick design convergence, and test results on real hardware confirm that the SAR image processing system offers acceptable quality of image output.
A novel approach is presented for change detection of very high resolution (VHR) remote sensing images in this paper, which is achieved by an improved watershed segmentation and mutual correlation. Specifically, the i...
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ISBN:
(纸本)9781849199940
A novel approach is presented for change detection of very high resolution (VHR) remote sensing images in this paper, which is achieved by an improved watershed segmentation and mutual correlation. Specifically, the input multitemporal images are watershed segmented separately in the first stage. And then fuse the segmentation regions of two segmented images, which is also a combination of object outlines in other words. Finally, the change mask can be acquired by the mutual correlation method. Experimental results show the superiority of the proposed method over the Markov random filed (MRF) method to the VHR urban optical remote sensing images.
Computer-aided diagnosis (CAD) technology can improve the detection of abnormal. Such as calcifications, masses, and architectural distortion. Among the three abnormals, architectural distortion is the most difficult ...
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ISBN:
(纸本)9781509037117
Computer-aided diagnosis (CAD) technology can improve the detection of abnormal. Such as calcifications, masses, and architectural distortion. Among the three abnormals, architectural distortion is the most difficult one to detect for both radiologists and CAD systems. In this article, we use automatic architectural distortion detection method to locate initial suspicious areas. Then, combine the transfer learning to detect architectural distortion, the reason we use transfer learning is the number of samples of architectural distortion in mini-MIAS database and Digital Database for Screening Mammography (DDSM) is small, and the number of malignant mass is much larger. The malignant mass and the architectural distortion are similar. Our objective is by transferring malignant mass information to improve the recognition rate of AD in the case of only a small amount of AD training samples.
Due to the existence of the large scale matrix transposition, the memory bandwidth becomes the bottleneck of the real-timeprocessing in spaceborne SAR imaging. The paper reports a preliminary study result of the memo...
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ISBN:
(纸本)9781849199940
Due to the existence of the large scale matrix transposition, the memory bandwidth becomes the bottleneck of the real-timeprocessing in spaceborne SAR imaging. The paper reports a preliminary study result of the memory architecture in the spaceborne SAR imaging system. It consists of algorithm summarizations, implementation difficulty discussions and processing requirement analysis. Then, a new memory architecture is being proposed to improve memory access efficiency and its implementation is specified. Finally, results of different methods are compared and imaging results validates the presented memory architecture.
This paper presents a method of the implementation of a verification platform. The platform is applied to an ASIC chip designed for the key algorithm of SAR signal processing. The design is a complicated process and t...
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ISBN:
(纸本)9781849199940
This paper presents a method of the implementation of a verification platform. The platform is applied to an ASIC chip designed for the key algorithm of SAR signal processing. The design is a complicated process and the chip function is computationally burdensome, thus the verification is difficult. Balancing the competing demands for efficiency, quality, time and cost, the verification platform is carefully designed using the Verilog language, with Synopsys VCS-MX2009 adopted. The experimental results show that the design errors of timing and anti-protocols have been exactly checked out and the verification coverage reaches 100% at last. The platform possesses satisfying characteristics such as high performance, fine configurability, flexibility and expansibility.
This paper proposes and implements the relative radiometric correction for remote sensing images based on Vivado HLS with FPGA. This design not only simplifies the development process, but successfully achieved the pu...
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ISBN:
(纸本)9781849199940
This paper proposes and implements the relative radiometric correction for remote sensing images based on Vivado HLS with FPGA. This design not only simplifies the development process, but successfully achieved the purpose of improving the image quality of remote sensing image. Firstly, this paper gives a brief analysis on the radiometric correction algorithm based on histogram matching correction, and then using C to complete the hardware development of FPGA by HLS. The results validate the feasibility of histogram correction based on HLS.
This paper compared the differences between monostatic SAR and bistatic SAR by introducing the spatial spectrum theory. The signal models of different radar systems are analyzed. The SAR image processing is considered...
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ISBN:
(纸本)9781849199940
This paper compared the differences between monostatic SAR and bistatic SAR by introducing the spatial spectrum theory. The signal models of different radar systems are analyzed. The SAR image processing is considered as a Fourier transformation in the spatial spectrum where the SAR echo corresponds to the sampling point. Three kind of SAR system are simulated using method of moment which ensures the authenticity of the simulations. The bistatic SAR can get lower frequency component than monostatic SAR and its resolution will be lower in twodimension condition.
Because of working in L band, geosynchronous synthetic aperture radar interferometry (GEO InSAR) and differential interferometry (GEO D-InSAR) system is sensitive to the interferometric phase screen errors introduced ...
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ISBN:
(纸本)9781849199940
Because of working in L band, geosynchronous synthetic aperture radar interferometry (GEO InSAR) and differential interferometry (GEO D-InSAR) system is sensitive to the interferometric phase screen errors introduced by ionosphere. However, conventional ionosphere time-spatial freezing model used in Low Earth Orbit (LEO) SAR is no longer valid due to the long integration time and large imaging width of GEO SAR. In this paper, especially aimed at the time-spatial background ionosphere variation, we firstly theoretically analyzed its impacts on GEO InSAR phase screen. Then, some simulations were conducted by virtue of the real Total Electron Content (TEC) data to study the impacts. The results suggest the serious errors will be brought in the GEO InSAR phase screen by the time-spatial background ionosphere variation.
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