Liu Congfeng

Improved pattern synthesis method with linearly constraint minimum variance criterion

For the pattern synthesis method of the arbitrary array antenna with the linearly constraint minimum variance criterion (LCMV-PS), the primary disadvantage is its poor adaptability, namely its performance is determined by the iterative coefficient. In order to improve its performance, the effect of the relative amplitude between synthesis pattern and its reference upon the pattern synthesis is considered adequately, via adding a proportion constant to the iterative formula, not only the pattern synthesis efficiency is improved, but also the adaptability is extended. By the novel improvement for its iterative coefficient, the application area and adaptability of the pattern synthesis method are enhanced. The last simulation attests its correctness and effectiveness.

Canonical framework for multi-channel SAR-GMTI*

Abstract Synthetic aperture radar (SAR) systems have become an important tool for fine-resolution mapping and other remote sensing operations. The multi-channel SAR ground moving-target indication (GMTI) must process its data to produce not only the image of surveillance area but also the information of the ground moving-targets. The topic of moving-target detection in clutter has been extensively studied, and there are many methods that are used to detect moving targets, such as displaced phase center antenna (DPCA) method, along-track interfero-metric (ATI) phase, space-time adaptive processing (STAP), or some other metrics. A canonical framework is proposed that encompasses all the multi-channel SAR-GMT methods, namely, DPCA and ATI. The statistical test metric for multi-channel SAR-GMTI is established in a simple form, via the definition of the complex central Wishart distribution, to deduce the statistics of the test metric, and the probability distribution of the test metric for multi-channel SAR-GMTI has the complex central Wishart distribution of 1 × 1 case, namely the χ 2 distribution. The theory foundation offers the possibility to construct the united multi-channel SAR-GMTI detector, and derives the constant false alarm rate (CFAR) detector tests for separating moving targets from clutter.

Canonical Framework for ATI and DPCA

The topic of moving-target detection in clutter has been extensively studied, there are many methods, such as along-track interferometric (ATI) phase, displaced phase center antenna (DPCA) method, space-time adaptive processing (STAP), or some other metrics. A canonical framework is proposed that encompasses ATI and DPCA. The statistical test metric for ATI and DPCA is established in an simple form, via the definition of the complex central Wishart distribution, deduces the statistics of the test metric, the probability distribution of the test metric for ATI and DPCA have the complex central Wishart distribution of 1times1 case, namely the chi2- distribution. The theory foundation offers the possibility to construct the united multi-channel SAR GMTI detector, and derive the constant false-alarm rate (CFAR) detector tests for separating moving targets from clutter.

Fast Algorithm for Root-MUSIC with Real-Valued Egendecomposition

A fast algorithm for the root-MUSIC with real-valued eigendecomposition is considered. This algorithm reduces the computational complexity in the eigenanalysis stage of root-MUSIC because it exploits the eigendecomposition of a real-valued covariance matrix. The asymptotic performance of root-MUSIC with real-valued eigendecomposition (RVED-root-MUSIC) is analyzed and compared with that of conventional root-MUSIC. The coefficients of the polynomial for root MUSIC is deduced and given the concrete calculation formula, so that the speed of polynomial finding roots gets the bigger exaltation. The results of this comparison show identical asymptotic properties of both algorithms in the case of uncorrelated sources and a better performance of RVED-root-MUSIC in scenarios with partially correlated or fully coherent sources. Additionally, our simulations and the results demonstrate an improved performance of RVED-root-MUSIC relative to conventional root-MUSIC