Adaptive MTI Research Articles

Comparative Experimental Investigations of Adaptive and Non-adaptive MTI Systems in Pulse Radars of Various Applications and Wave Ranges

Comparative Experimental Investigations of Adaptive and Non-adaptive MTI Systems in Pulse Radars of Various Applications and Wave Ranges

The Adaptive MTI System with Minimized Magnitude and Phase Distortions of the Processed Chirp Echo Signal

The article exhibits some issues associated with the nonlinear phase-frequency characteristic of the notch whitening filter based on a two-channel adaptive system with cross-control of filter weights arising from the chirp signal processing and with the distortion of such a signal caused by this nonlinearity. An adaptive MTI system is proposed, using which the distortion of the useful chirp signal contained in the input unclassified observation sample is minimized during adaptive notch processing with cross-control of weights.

Airborne adaptive MTI scheme with preventing the whitening of the target

A new airborne MTI scheme that applies to non-homogeneous clutter environment is presented. Results of simulation have proved that the scheme has a superior ground clutter suppression performance and can effectively prevent the whitening of a target.

Adaptive airborne MTI with tapered antenna arrays

Space–time adaptive processing achieves optimum clutter rejection for airborne radar. Several aspects of space–time adaptive processing in the design phase of an operational system are addressed: use of a realistic array antenna (planar circular, 1204 elements); forward-looking arrangement; comparison with conventional temporal MTI processing; effect of tapering and impact of jamming. Results of this work contribute to the trilateral AMSAR project.

Polish radar technology

Polish radar research and development since 1953 is reviewed, covering the development and production of surveillance radars, height finders, tracking radars, air traffic control (ATC) radars and systems, and marine and Doppler radars. Some current work, including an L-band ATC radar for enroute control, a weather channel for primary surveillance radar, signal detection in non-Gaussian clutter, adaptive MTI filters and postdetection filtering, and a basic approach to radar polarimetry, is examined.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Adaptive airborne MTI with two-dimensional motion compensation

Clutter returns received by an airborne radar exhibit a Doppler bandwidth which depends on the platform speed, beamwidth and wavelength. Echoes of slow targets may, therefore, be buried in the clutter band and are difficult to detect. Perturbations of the flight path due to the flight dynamics of the aircraft and wind effects may cause further degradation of the MTI performance. It has been shown in earlier papers of the author that space-time FIR filters applied to the output signals of a linear array antenna can be used to compensate adaptively for the flight path component of the platform motion so that a large improvement in signal-to-clutter-plus-noise ratio (SCNR) can be obtained. Such filters are referred to as TASTE (techniques for airborne slow target extraction) methods. In the paper these ideas are extended to the compensation of transversal velocity components by means of a planar array with horizontal orientation. The influence of the system bandwidth is also investigated. The results obtained can be generalised to compensate for three-dimensional perturbations of the flight path without using an inertial navigation device.

Adaptive airborne MTI: an auxiliary channel approach

The suppression of ground clutter returns received by an airborne radar is basically a two-dimensional filtering problem, because the clutter echoes depend on two parameters (velocity, azimuth) instead of velocity only as in case of ground-based radars. This requires two-dimensional sampling (in space and time) of the backscattered echo field, which in practice is fulfilled by a coherent pulse Doppler phased array radar. Previous studies have shown that the space-time clutter covariance matrix of the order NM × NM (N is the number of sensors, M the number of echoes) has only N + M clutter eigenvalues (instead of NM), which means that the signal vector space can be reduced. In the paper an adaptive radar receiver with AMTI (airborne MTI) capability is shown and discussed. It is shown that this AMTI receiver approximates well the theoretical optimum; however, the computational expense is drastically reduced. In view of the dramatic progress in the field of microelectronics and algorithms (e.g. systolic arrays), one can expect that such AMTI receivers will be realisable for real-time applications in the near future.

Simulation of an adaptive MTI in a monopulse FMCW radar sensor

A range-doppler spread target model is modified to obtain a clut ter model by including the effect of beam and range gate shape. This clutter modeling is then applied in a simulation of an FMCW radar sensor that uses an adaptive moving target indicator (AMTI) and a monopulse antenna to detect slow-moving ground targets. The ability of the AMTI to discriminate a slow-moving point target from ground clutter is shown via simulation.

Performance Compparison of Optimum and Conventional MTI and Doppler Processors

The performance of an optimum radar signal processor and more conventional techniques (such as MTI, adaptive MTI, and cqherent integration) are compared. A mathematical method is suggested and applied to several cases of practical interest. A number of operative conditions are discovered in which the conventional processing techniques give very poor performance and the optimum radar processor becomes necessary.

Correction to "Design and Evaluation of an Adaptive MTI Filter"

Correction to "Design and Evaluation of an Adaptive MTI Filter"