Moving target indication

About: Moving target indication is a research topic. Over the lifetime, 2653 publications have been published within this topic receiving 32435 citations.

Apparatus for compressing the amplitude range of signals

Abstract: This invention relates to electrical circuits, and more particularly to a circuit for reducing the dynamic range of amplitude of a series of signals. In a moving target indication radar system of the type disclosed in the copending application of Robert H. Dicke, entitled "Communication system,"...

High-Accuracy Measurement of Small Movement of an Object behind Cloth Using Airborne Ultrasound

Abstract: The acoustic measurement of vital information such as breathing and heartbeat in the standing position whilst the subject is wearing clothes is a difficult problem. In this paper, we present the basic experimental results to measure small movement of an object behind cloth. We measured acoustic characteristics of various types of cloth to obtain the transmission loss through cloth. To observe the relationship between measurement error and target speed under a low signal-to-noise ratio (SNR), we tried to measure the movement of an object behind cloth. The target was placed apart from the cloth to separate the target reflection from the cloth reflection. We found that a small movement of less than 6 mm/s could be observed using the M-sequence, moving target indicator (MTI) filter, and tracking phase difference, when the SNR was less than 0 dB. We also present the results of theoretical error analysis in the MTI filter and phase tracking for high-accuracy measurement. Characteristics of the systematic error were clarified.

On the design of staggered moving target indicator filters

Abstract: The problem of moving target indicator (MTI) filter design for radar systems with non-uniform (staggered) pulse repetition intervals is examined. The goal is to realise and then utilise a trade-off in the design of MTI filter between the conflicting requirements of high suppression of undesired signal (clutter echo) and minimal suppression of desired signal (target echo). To that aim, three design methodologies, namely, least squares, convex optimisation and min–max error, are studied. The numerical results indicate that the presented designs yield high-performance MTI filters which are easily applicable to a variety of operational scenarios. A ready-to-use source code for the design of suggested filters is also provided.

A Novel Moving Target Detection Method Based on RPCA for SAR Systems

Abstract: Clutter background suppression and velocity estimation for moving targets are two critical problems in synthetic aperture radar–ground moving target indication (SAR-GMTI). A robust principal component analysis (RPCA) method is used to separate the sparse matrix of moving targets from the low-rank matrix of static backgrounds by using amplitude information in the image domain. However, the nonsparsity of the moving target echoes limits the performance of the RPCA in SAR-GMTI, and the velocity of the moving target cannot be estimated since the phase information is destroyed by the soft-thresholding operator in the RPCA process. To solve these problems, a novel moving target detection method based on RPCA (NRPCA) for SAR systems is proposed in this article. An atomic norm-based optimization program is first constructed to transform the data sparsity requirement into a moving target sparsity requirement. Although this optimization program is NP-hard, it is transformed to semidefinite programming by relaxation. Furthermore, accurate velocity estimation is performed using dual function theory and the alternating direction method of multipliers (ADMM) algorithm while the selection of the sparsity order k is avoided. Simulations and analyses based on experimental data illustrate the effectiveness of the proposed method.

System and method for combining displaced phase center antenna and space-time adaptive processing techniques to enchance clutter suppression in radar on moving platforms

Abstract: A system and method are disclosed for enhancing the suppression of clutter and target detection in a radar system located on a moving platform. For example, a radar system including an MTI subsystem is located on a moving platform (e.g., ship-borne, airborne or space- based radar system) with a DPCA processing unit located nearer to the front end of the radar receiver, and a STAP processing unit located nearer to the back end. The DPCA processing unit provides gross cancellation and suppression of the received clutter signals, and the STAP processing unit provides fine tuning for the clutter suppression process. In other words, the front end DPCA processing unit removes most of the rapidly varying clutter, which gives the back end STAP processing unit a more benign clutter environment to process. As such, using a DPCA processing unit on a space -based radar platform improves system performance, because the space- based platform is relatively stable and not subject to air turbulence or wave motion. Also, using a DPCA processing unit provides independence from clutter statistics, which is important because relatively little empirical clutter data is available from space-based radar platforms. Using a STAP processing unit for clutter suppression on the space-based radar platform provides fine tuning of the suppression process.