Yanping Li

A Novel Low RCS Microstrip Antenna Using Aperture Coupled Microstrip Dipoles

A microstrip antenna composed of parallel dipoles of different widths fed by rectangular slots cut in the ground plane of a microstrip line is designed for low RCS property. Based on the surface current distribution on the patch, the effects of cutting slots in the patch and the ground plane on the resonant modes which have a unique relationship with the radiation performance and RCS response of a microstrip antenna are discussed. By properly controlling resonant modes, the proposed antenna realizes good radiation performance and low RCS. Compared to the rectangular patch antenna with the same operating frequency, the proposed antenna, with only a 0.5 dB reduction of gain, has an RCS reduction of approximately 2–10 dB in the vicinity of the peaks illuminated by the plane wave from different incidence directions. Additionally, the antenna bandwidth does not decrease, which overcomes the problem that the RCS reduction techniques cause the loss of bandwidth.

Novel microstrip antenna array with low RCS

In this paper, a novel microstrip antenna array with low RCS (Radar Cross Section) is presented and analyzed. Under the condition that the incident wave is in grazing angle, a single microstrip antenna which uses the techniques of miniaturization and ground-cut slots is chosen as an element of a 2×2 antenna array. Analysis and optimization of the arrangement of the array is made to realize more reduction of the RCS. The measured results of radiation performance accord with the simulation results, which imply that this novel method is feasible.

Tracking Multiple Video Objects in Complex Scenes

Tracking multiple objects is an essential task for many video applications. One of the key technical issues for effectively tracking the objects is to deal with the shadows and occlusions in video scenes. In this paper, an adaptive shadow suppression method, which combines chrominance and texture features, is proposed. Moreover, in order to handle the occlusions effectively, the relationship between the bounding boxes of object at previous and present time has been taken into account, so that the color distributions of objects are recorded when they merge and the identity of each object is certified by the Bhattacharyya distance when they separate. Experimental results on tracking objects in various video sequences demonstrate the robustness and efficiency of the proposed algorithm.

A Combined Pca/Snake Model for Precise Object Contour Extraction

An extended PCA algorithm to extract moving objects is presented in this paper. In the algorithm, three frames are sufficient for the extraction of for rigid or non-rigid objects. In order to obtain a precise contour of moving object, a snake model is adopted to process the object detection results. In our experiments, a range of image sequences is used to test the combined PCAsnake model. The results show that the proposed algorithm can extract the moving objects accurately and its speed is improved over the conventional PCA model.