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公开(公告)号：US4780718A
公开(公告)日：1988-10-25
申请号：US745729
申请日：1985-06-17
申请人： Ralph E. Hudson , Yoji G. Niho
发明人： Ralph E. Hudson , Yoji G. Niho
摘要： A technique is disclosed for encoding SAR image data to achieve data compression. In the image encoding stage, the SAR image is transformed into a list of high reflectivity radar discretes and a small array of frequency filters. In the target list, the location data and intensity levels above the local average background clutter are tabulated for a predetermined number of the highest intensity radar discretes. The array of frequency filters is divided into three zones; the inner, middle, and higher frequency zones relative to the d.c. filter. Only the inner and middle zones of filters are retained and the outer filters are discarded, thus acheiving the desired data reduction. The inner zone filters are quantized to a higher level of precision than the middle zone of filters. The saturation levels of the filters are determined adaptively. In the decoding stage, the original SAR image is reconstructed from the radar discrete list and the small array of frequency filters.
摘要翻译： 公开了一种用于编码SAR图像数据以实现数据压缩的技术。 在图像编码阶段，SAR图像被转换为高反射率雷达离散列表和一系列频率滤波器。 在目标列表中，对于预定数量的最高强度雷达分立体，列出了高于局部平均背景杂波的位置数据和强度水平。 频率滤波器阵列分为三个区域; 内，中，高频区相对于直流。 过滤。 仅保留过滤器的内部和中部区域，并且丢弃外部过滤器，从而实现所需的数据减少。 内部区域滤波器被量化到比中间滤波器区域更高的精度水平。 自适应地确定滤波器的饱和电平。 在解码阶段，从雷达离散列表和频率滤波器的小阵列重建原始的SAR图像。
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2.发明授权公开(公告)号：US07714768B2
公开(公告)日：2010-05-11
申请号：US11904715
申请日：2007-09-28
IPC分类号： G01S13/90
CPC分类号： G01S7/003 , G01S13/9011
摘要： Provided is a non-statistical method for compressing and decompressing complex SAR data derived from reflected energy. The method includes selecting a first FFT to provide a target ratio of pixel spacing to resolution. A second FFT is then selected which is smaller than the first FFT. The data is zero-padded to fill the second FFT and transformed to provide at least one transfer frequency. This transfer frequency is then transferred to the at least one remote site. At the remote site the second FFT is inverted to restore the data from the received transfer frequency. The restored data is then zero-padded again to fill the first FFT. The first FFT is then used to transform the zero-padded restored data to provide a data set of points with the target ratio of pixel spacing to resolution.
摘要翻译： 提供了一种用于压缩和解压缩从反射能量导出的复数SAR数据的非统计方法。 该方法包括选择第一FFT以提供像素间隔与分辨率的目标比率。 然后选择小于第一FFT的第二FFT。 数据被填充以填充第二FFT并被转换以提供至少一个传送频率。 然后将该传送频率传送到至少一个远程站点。 在远程站点，第二FFT被反转以从接收的传送频率恢复数据。 然后，恢复的数据再次进行零填充以填充第一FFT。 然后使用第一FFT来对补零的恢复数据进行变换，以提供具有像素间距与分辨率的目标比例的点的数据集。
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公开(公告)号：US5495540A
公开(公告)日：1996-02-27
申请号：US322117
申请日：1994-10-12
申请人： Robert T. Frankot , Ralph E. Hudson
发明人： Robert T. Frankot , Ralph E. Hudson
CPC分类号： G06T7/003 , G06T7/0034
摘要： A method for automatically selecting subareas from reference image data such that registration accuracy is optimized between images. Optimal subarea selection reduces the on-line computation and reference data storage required for multi-subarea correlation or, alteratively, improves its effectiveness. Example results for a synthetic aperture radar (SAR) image are described. The results indicate that the automatic subarea selection method of the present invention reduces on-line computation by a factor of 2 to 3 (relative to random subarea selection) without degradation in accuracy. The present selection method minimizes the predicted total mean squared registration error (MSE). The total MSE is predicted in terms of the position and predicted measurement covariance (derived from local image statistics) of each candidate subarea. Combinatorial optimization procedures select a predetermined number of subareas to minimize total MSE. The present method jointly considers the quality and position for each local measurement, optimally handles any order polynomial model, and includes bounds on the uncertainty of registration parameters.
摘要翻译： 一种用于从参考图像数据自动选择子区域的方法，使得在图像之间优化注册精度。 最佳分区选择减少了多分区相关所需的在线计算和参考数据存储，或者改变其效率。 描述了合成孔径雷达（SAR）图像的示例结果。 结果表明，本发明的自动分区选择方法将在线计算减少了2到3倍（相对于随机子区域选择），而不会降低精度。 本选择方法使预测的总均方格注册误差（MSE）最小化。 根据每个候选子区域的位置和预测的测量协方差（来自局部图像统计）来预测总MSE。 组合优化程序选择预定数量的子区域以最小化总MSE。 本方法共同考虑每个局部测量的质量和位置，最优化处理任意阶多项式模型，并包括对注册参数不确定度的界限。
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公开(公告)号：US5448241A
公开(公告)日：1995-09-05
申请号：US249488
申请日：1994-05-26
CPC分类号： G01S13/90 , G01S13/882
摘要： A terrain height radar system and processing method comprising a high resolution synthetic aperture radar (SAR) mounted on an air vehicle and a SAR signal processor containing a signal processing algorithm or method for computing terrain height and radar backscatter power. The system contains motion sensing and navigation functions that also provide data to the signal processor to provide motion compensation. Signal processing algorithms in the method compensate for planar motion of the air vehicle for variations of terrain height in the field of view. The algorithms also compensate for nonplanar motion of the radar, and for scatterers in or very near to a reference plane in the field of view. The algorithms exploit defocusing due to displacement from the reference plane to estimate the terrain height above the reference plane. The algorithm is computationally efficient because the bulk of the radar signal processing is common to both the SAR function and the terrain height estimation function. The following processing method is implemented. The synthetic array radar is operated to produce out-of-plane motion and generating radar return signals derived therefrom. The radar return signals are processed to compensate for relative motion, generate ground plane polar format data, generate range compressed data, and generate autofocused data. Azimuth compressed data is generated by focusing uncompressed azimuth data for each of many discrete terrain height reference levels, compressing the focused data using a weighted FFT, temporarily recording the magnitude of each pixel, storing separate image magnitude values corresponding to each terrain height reference level for each pixel and outputting the largest of these magnitudes for each pixel as a radar cross section value of that pixel, and outputting the height reference level at which that maximum occurred as the height of that pixel. Interpolation may be used to refine the height estimate. The strong scatterer signal is then canceled by estimating the amplitude phase height and azimuth of the strong scatterer, using these parameters to determine a contribution in the uncompressed data set due to the strong scatterer, subtracting this contribution from the uncompressed data, and repeating the amplitude phase height and azimuth height estimating step to provide for for improved accuracy.
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公开(公告)号：US5610610A
公开(公告)日：1997-03-11
申请号：US195555
申请日：1988-05-18
申请人： Ralph E. Hudson , Howard S. Nussbaum , Ernest Chen
发明人： Ralph E. Hudson , Howard S. Nussbaum , Ernest Chen
IPC分类号： G01S13/90
CPC分类号： G01S13/9035
摘要： An inverse synthetic array radar (ISAR) system provides for improving the resolution of an ISAR image by providing compensation for non-uniformity in the magnitude of the angular velocity of a rotating target as the target rotates to generate the synthetic-aperture-angle, and enables use of a larger synthetic-aperture angle, without compromising ISAR image quality with respect to smear. The preferred embodiment records sampled data signals to generate a collected-data matrix indexed in each of two dimensions on the basis of uniform increments of time, and performs data processing to produce a translated data matrix indexed in a dimension on the basis of uniform increments of synthetic-aperture angle. Further processing of the translated data matrix produces data in a buffer for controlling a display device for the ISAR image.
摘要翻译： 逆合成阵列雷达（ISAR）系统提供了通过对目标旋转以产生合成孔径角度的旋转目标的角速度的大小的不均匀性进行补偿来提高ISAR图像的分辨率，以及 可以使用更大的合成孔径角度，而不会影响ISAR图像质量。 优选实施例记录采样数据信号，以基于均匀的时间增量生成在二维中每一个中索引的收集数据矩阵，并执行数据处理以产生在维度上索引的经翻译的数据矩阵， 合成孔径角度。 翻译数据矩阵的进一步处理在用于控制ISAR图像的显示装置的缓冲器中产生数据。
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公开(公告)号：US5488374A
公开(公告)日：1996-01-30
申请号：US323414
申请日：1994-10-14
CPC分类号： G01S13/9023 , G01S7/292
摘要： Apparatus including a multi-scale adaptive filter for smoothing interferometric SAR (IFSAR) data in areas of low signal-to-noise ratio (SNR) and/or coherence while preserving resolution in areas of high SNR/coherence. The multi-scale adaptive filter uses simple combinations of multiple linear filters applied to a complex interferogram. The multi-scale adaptive filter is computationally efficient and lends itself to parallel implementation. A pyramid architecture comprising a plurality of cascaded stages is employed which reduces the computational load and memory required for implementation of the processing algorithm. The multi-scale adaptive filter implements a processing algorithm that may be applied to standard IFSAR data. Its input is a complex interferogram (the conjugate product of two complex images) and its output is a filtered interferogram (A) which is passed to an information extraction processor, that extracts a terrain elevation map, for example. The adaptive filter incorporates linear filters at two or more scales (i.e. filter impulse response widths) whose outputs are combined in a data-dependent manner. The combination rules result in an output interferogram (A) that is filtered heavily in areas of low coherence and receives little or no filtering in areas of high coherence. The combination rules use a coherence measure that is a simple nonlinear function of the linear filter outputs themselves.
摘要翻译： 包括用于在低信噪比（SNR）和/或相干性区域中平滑干涉SAR（IFSAR）数据的多尺度自适应滤波器的装置，同时在高SNR /相干性区域保持分辨率。 多尺度自适应滤波器使用应用于复杂干涉图的多个线性滤波器的简单组合。 多尺度自适应滤波器具有计算效率，适用于并行实现。 采用包括多个级联级的金字塔结构，其减少了实现处理算法所需的计算负荷和存储器。 多尺度自适应滤波器实现了可应用于标准IFSAR数据的处理算法。 其输入是复杂的干涉图（两个复合图像的共轭乘积），其输出是经过滤波的干涉图（＆amp; upbar＆A），传递给信息提取处理器，例如提取地形高程图。 自适应滤波器以两个或多个尺度（即滤波器脉冲响应宽度）组合线性滤波器，其输出以数据相关的方式组合。 组合规则导致输出干涉图（＆upbar＆A）在低相干区域中被大量过滤，并且在高一致性区域中几乎或不进行滤波。 组合规则使用相干度测量，它是线性滤波器输出本身的简单非线性函数。
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公开(公告)号：US5248976A
公开(公告)日：1993-09-28
申请号：US798783
申请日：1991-11-27
申请人： Yoji G. Niho , Ralph E. Hudson , Tammy L. Flanders
发明人： Yoji G. Niho , Ralph E. Hudson , Tammy L. Flanders
IPC分类号： G01S13/90
CPC分类号： G01S13/90
摘要： A method and autofocus processor that is adapted to automatically correct focus phase errors associated with synthetic array radar signals. The method comprises processing the synthetic array radar signals to produce a SAR image; identifying and locating potential targets contained in the SAR image; storing the range bin and azimuth location of the target in a target list; bandpass filtering the SAR signals associated with the target scatterer to remove the interference therefrom; forming the pulse pair product of the phase history samples from each reference target to produce a differential phase function; integrating the differential phase function over all reference targets to provide the averaged differential phase history associated therewith; interpolating the averaged differential phase function to restore the original time scale and number of samples; and computing the focus error from interpolated differential phase history. The focus error is estimated as a weighted average of the phase history of the detected scatterers. The autofocus processor automatically finds targets and combines data from multiple scatterers effectively and efficiently. The autofocus processor extends the range and resolution limits of SAR systems, and enables the effective use of a SAR sensor with less expensive motion compensation function. The autofocus processor also decouples the SAR sensor (including motion sensors) from its SAR processor, so that the autofocus processor produces better images, no matter what sensor is employed.
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8.发明授权Method and system for reducing phase error in a phased array radar beam steering controller 失效相控阵雷达波束转向控制器减少相位误差的方法和系统
公开(公告)号：US4924232A
公开(公告)日：1990-05-08
申请号：US265079
申请日：1988-10-31
CPC分类号： H01Q3/385
摘要： The method and system for reducing phase error of phased array radar beam steering controllers having digitally controlled phase shifters includes the monitoring of individual digitally controlled phase shifter elements, determining an additive phase correction to reduce the number of failed phase shifter elements, determining whether said additive phase correction is achievable by comparing the stuck bit state at each said failed changers element with said additive phase correction and adjusting the phase commands to the nearest values which can be achieved if the additive phase correction is unachievable.
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9.发明申请公开(公告)号：US20100066598A1
公开(公告)日：2010-03-18
申请号：US11904715
申请日：2007-09-28
IPC分类号： G01S13/90
CPC分类号： G01S7/003 , G01S13/9011
摘要： Provided is a non-statistical method for compressing and decompressing complex SAR data derived from reflected energy. The method includes selecting a first FFT to provide a target ratio of pixel spacing to resolution. A second FFT is then selected which is smaller than the first FFT. The data is zero-padded to fill the second FFT and transformed to provide at least one transfer frequency. This transfer frequency is then transferred to the at least one remote site. At the remote site the second FFT is inverted to restore the data from the received transfer frequency. The restored data is then zero-padded again to fill the first FFT. The first FFT is then used to transform the zero-padded restored data to provide a data set of points with the target ratio of pixel spacing to resolution.
摘要翻译： 提供了一种用于压缩和解压缩从反射能量导出的复数SAR数据的非统计方法。 该方法包括选择第一FFT以提供像素间隔与分辨率的目标比率。 然后选择小于第一FFT的第二FFT。 数据被填充以填充第二FFT并被转换以提供至少一个传送频率。 然后将该传送频率传送到至少一个远程站点。 在远程站点，第二FFT被反转以从接收的传送频率恢复数据。 然后，恢复的数据再次进行零填充以填充第一FFT。 然后使用第一FFT来对补零的恢复数据进行变换，以提供具有像素间距与分辨率的目标比例的点的数据集。
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10.发明授权公开(公告)号：US07307580B2
公开(公告)日：2007-12-11
申请号：US11333497
申请日：2006-01-17
IPC分类号： G01S13/90
CPC分类号： G01S7/003 , G01S13/9011
摘要： Provided is a non-statistical method for compressing and decompressing complex SAR data derived from reflected energy. The method includes selecting a first FFT to provide a target ratio of pixel spacing to resolution. A second FFT is then selected which is smaller than the first FFT. The data is zero-padded to fill the second FFT and transformed to provide at least one transfer frequency. This transfer frequency is then transferred to the at least one remote site. At the remote site the second FFT is inverted to restore the data from the received transfer frequency. The restored data is then zero-padded again to fill the first FFT. The first FFT is then used to transform the zero-padded restored data to provide a data set of points with the target ratio of pixel spacing to resolution.
摘要翻译： 提供了一种用于压缩和解压缩从反射能量导出的复数SAR数据的非统计方法。 该方法包括选择第一FFT以提供像素间隔与分辨率的目标比率。 然后选择小于第一FFT的第二FFT。 数据被填充以填充第二FFT并被转换以提供至少一个传送频率。 然后将该传送频率传送到至少一个远程站点。 在远程站点，第二FFT被反转以从接收的传送频率恢复数据。 然后，恢复的数据再次进行零填充以填充第一FFT。 然后使用第一FFT来对补零的恢复数据进行变换，以提供具有像素间距与分辨率的目标比例的点的数据集。
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