Fujitsu Corporation

Chinese Academy of Sciences

Pingping Lu

Yu Wang

Bo Li

Rujie Liu

YongHua Cai

Liang Li

Junfeng Li

ZhiYuan Xue

YiJiang Nan

An azimuth ambiguity suppression method for a spaceborne SAR in spatially non-uniform sampling relates to the technical field of radars. The method includes the following steps: step 1: compensating for a phase difference between the channels according to the locations of transmitting and receiving stations for channel echoes; step 2: calculating an equivalent azimuth sampling location of each channel at the moment of each pulse transmission; step 3: sorting the equivalent azimuth sampling locations of all channels and their corresponding echoes after the phase difference between the channels is compensated in ascending order; and step 4: calculating reconstructed echoes from the sorted equivalent azimuth sampling locations and corresponding echoes after the phase difference between the channels is compensated, by using an adaptive weight-conjugate gradient-Toeplitz matrix (ACT) algorithm. According to the present disclosure, a relative distance between the channels is not required to remain unchanged, which greatly expands the scope of application of azimuth multi-channel SAR echo reconstruction.

Azimuth ambiguity suppression method for spaceborne SAR in spatially non-uniform sampling

The present disclosure discloses a method for suppressing the azimuth ambiguity of multi-channel SAR systems based on channel cancellation, which falls within the field of radar signal processing. The method includes: imaging echoed of the multi-channel SAR system based on a linear mapping reconstruction algorithm to obtain a reconstructed high-resolution wide-swath image; estimating positions of the azimuth ambiguity regions of the reconstructed high-resolution wide-swath image; extracting ambiguity images in the azimuth ambiguity regions based on channel cancellation and the refocusing algorithm; and suppressing a repetitive ambiguity image in imaging the echo of the multi-channel SAR system. The method weakens the influence of the original image on azimuth ambiguity extraction, improves the performance of ambiguity suppression, and solves the problem of additional repetitive ambiguity in multi-channel SAR systems by reconstructing the ambiguity signal, and improves the image quality of the multi-channel SAR system, which has great value for subsequent applications such as SAR image interpretation.

Method for suppressing azimuth ambiguity of multi-channel SAR systems based on channel cancellation

An apparatus and a method for data processing are provided. The apparatus for data processing includes a modeler configured to build an occlusion object model for an image containing an occlusion object; a renderer configured to render the occlusion object model according to a geometric relationship between the occlusion object and a face image containing no occlusion object, such that the rendered occlusion object image and the face image containing no occlusion object have same scale and attitude; and a merger configured to merge the face image containing no occlusion object and the rendered occlusion object image into an occluded face image. With the data processing apparatus and the data processing method face data enhancement, face data in the case of having an occlusion object is generated, so that the number of face training data sets can be effectively increased, thereby improving performance of a face-related module.

Apparatus and method for data processing

A method and apparatus for evaluating an illumination condition in a face image is provided by decomposing a face image into illumination feature components and face feature components; extracting determined areas in the face image; calculating a maximum luminance feature, a minimum luminance feature and an illumination direction feature according to the decomposed illumination feature components in the determined areas. The illumination condition in the face image is evaluated according to the maximum luminance feature, the minimum luminance feature and the illumination direction feature.

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Beijing, China

Pingping Lu