scispace - formally typeset
Search or ask a question

Showing papers on "Moving target indication published in 1977"


Patent
11 Apr 1977
TL;DR: In this paper, a programmable signal processor is described for use with an array radar, which can be programmed to have any desired frequency response and can be adapted as a function of antenna beam position, range bin sector, or time.
Abstract: A programmable signal processor is disclosed for use with an array radar. e programmable signal processor has quadrature channel, moving target indicators followed by post detection integration. The moving target indicators can be programmed to have any desired frequency response and can be adapted as a function of antenna beam position, range bin sector, or time. The processor also contains a high speed buffer which provides the capability to record, in real time, unprocessed raw video as well as corresponding processed moving target indicators and integrator outputs. The signal processor simultaneously processes the in-phase and quadrature components of the input signal. The output processed video signal is a digital representation of the input signal with fixed or slow moving clutter reduced and the signal-to-noise ratio improved by the response of the moving target indicator filter and the integrator respectively.

22 citations


01 Jun 1977
TL;DR: In this article, the authors present an antenna dilemma resulting from operation with instantaneous bandwidths greater than a decade, and present a solution to the very practical problem of obtaining a large energy content in an impulsive radiation is achieved by temporal-spatial compression.
Abstract: : From the birth of radar there has been a steady trend to increase the radiated bandwidth to obtain high resolution, extreme accuracy, target identification, and fine imagery. The ultimate radiated waveform to achieve these goals is an impulse. The present capability of generating multimegawatt subnanosecond impulsive waveforms is discussed including future limitations on the maximum peak power. A theoretical discussion of radiation and reception of impulse waveforms, as well as the experimental responses of selected antennas, is given. The paper presents an antenna dilemma resulting from operation with instantaneous bandwidths greater than a decade. Because of the antenna's inherent limitations, other transient waveform responses are also discussed including a ramp (double integrated impulse) and a monocycle (differentiated impulse) radar. MTI (Moving Target Indicator) operation is discussed showing that target blind velocities do not occur as with conventioal MTI radars. A solution to the very practical problem of obtaining a large energy content in an impulsive radiation is achieved by temporal-spatial compression. Here, a dispersive antenna is employed as a pulse compression network resulting in enhanced electromagnetic field intensity. Finally, some short-range impulse radar backscatter is shown for several targets. (Author)

7 citations


Journal ArticleDOI
TL;DR: In this paper, a frequency domain approach for determining the effective number of independent pulses at the output of a square law detector in a moving target indicator (MTI) system leads to a definition which gives the same asymptotic results as given by a previous definition.
Abstract: A frequency domain approach for determining the effective number of independent pulses at the output of a square law detector in a moving target indicator (MTI) system leads to a definition which gives the same asymptotic results as given by a previous definition.

5 citations


Journal ArticleDOI
TL;DR: Results demonstrate the efficacy of the Ahstrocst-An on-line digital moving target indicator OMTI system in isolating tricuspid value echoes in the heart from rib and chest wall echoes, and intracranial artery echoes from surrounding tissue.
Abstract: Ahstrocst-An on-line digital moving target indicator OMTI) system has been developed to isolate dynamic physiological target echoes from other relatively stationary anatomical structure echoes. Digital techniques were employed for data acquisition, storage, and subsequent subtraction. Results demonstrate the efficacy of the system in isolating tricuspid value echoes in the heart from rib and chest wall echoes, and intracranial artery echoes from surrounding tissue. Maximum arterial activity can also be detected. 4 0 -

4 citations


Proceedings ArticleDOI
William W. Shrader1
28 Dec 1977
TL;DR: MTI (Moving Target Indication) radar systems have been built for many years, based on sys-tem concepts evolved in the early 1950's as discussed by the authors, and many of the existing systems are very successful, even though their performance, measured in terms of MTI improvement factor or subclutter visibility, often falls far short of the performance predicted from linear theory.
Abstract: MTI (Moving Target Indication) radar systems have been built for many years, based on sys-tem concepts evolved in the early 1950's. Digital techniques now permit easier implementation, but do not change the basic concepts; staggered repetition periods to eliminate blind speeds; and MTI cancellers with the velocity response shaped by feed forward and feedback techniques. Many pf the existing systems are very successful, even though their performance, measured in terms of MTI improvement factor or subclutter visibility, often falls far short of the performance predicted from linear theory. The basic MTI concepts and definitions are presented, and the real problems of modern surface-based MTI radar systems are discussed. Future signal-processing techniques are postulated.

3 citations


01 Oct 1977
TL;DR: In this paper, a moving target detector (MTD) terminal radar processor system was evaluated to determine its capability to provide radar data suitable for utilization by the Automated Radar Terminal System.
Abstract: : The moving target detector (MTD) terminal radar processor system was evaluated to determine its capability to provide radar data suitable for utilization by the Automated Radar Terminal System. The major objective of testing was to compare the target detection in clutter performance of the MTD system with that of the best terminal radar processor system in the FAA inventory. The comparative tests were conducted using test signals and flight test aircraft. The test signals were used to determine false alarm rates, probability of detection, accuracy, velocity response, and subclutter visibility capabilities. Flight testing was performed to determine subclutter visibility, subweather visibility, and target resolution capabilities. Additional tests were performed to determine the compatibility of the MTD processor with terminal radar systems currently in use in the Federal Aviation Administration (FAA). The results of the tests demonstrated that the MTD system capability to detect targets in a clutter environment was much better than that of present FAA systems. It effectively eliminated all clutter experienced in the National Aviation Facilities Experimental Center (NAFEC) radar environment. The MTD processor is compatible with present FAA radar systems. (Author)

3 citations


Journal ArticleDOI
TL;DR: In this article, the reduction of the clutter cancellation ability of single and double-canceller MTI's is discussed with binominal weighting as a function of the number of levels and the spacing of the levels.
Abstract: To minimize hardware complexity, it is desirable to implement a digital moving target indicator (MTI) with the fewest number of quantization levels. The reduction of the clutter cancellation ability of single-and double-canceller MTI's is discussed with binominal weighting as a function of the number of levels and the spacing of the levels. The method of analysis is applicable to more complex MTI's as weil as nonuniform quantizers.

2 citations


Journal ArticleDOI
TL;DR: In this article, selected experimental results concerning complex radar-object backscattering and polarisation-dependent receiver responses are presented; in particular the optimum responses that are obtainable, and the experiments are related to a study of the applicability of adaptive polarisation for the improvement of target detection in clutter.
Abstract: Herein, selected experimental results concerning complex radar-object backscattering and polarisation-dependent receiver responses are presented; in particular the optimum responses that are obtainable. The objects are a boresight tower and an apartment-block conglomerate. The experiments are related to a study of the applicability of adaptive polarisation for the improvement of target detection in clutter.

2 citations


Journal ArticleDOI
TL;DR: A new Doppler detection process is described, which allows a better sensitivity and a simultaneous treatment of a whole line of observation is developed, based on the Moving Target Indicator process used in radar techniques.
Abstract: Doppler ultrasonic vascular visualization suffers presently from two main drawbacks, namely accuracy and time needed for acquisition of the images. Solutions to these problems are studied: a new Doppler detection process is described, which allows a better sensitivity; a mathematical approach and experimental observations were made. (2) a simultaneous treatment of a whole line of observation is developed, based on the Moving Target Indicator process used in radar techniques. A prototype has been designed and the first experimental results are reported.

2 citations


Proceedings ArticleDOI
28 Dec 1977
TL;DR: In this paper, a coherent optical processor is described which can be used to detect and locate objects in the sky thatmove against a background of fixed objects, and a succession of sky images is recorded by multiple exposure on photographic film with the imaging system stabilized on the stars.
Abstract: A coherent optical processor is described which can be used to detect and locate objects in the sky thatmove against a background of fixed objects. A succession of sky images is recorded by multiple exposure onphotographic film with the imaging system stabilized on the stars. Stars appear as points in the compositeimage, and moving objects create streaks. Space invariant pattern recognition is performed on this compositeimage by generating its two -dimensional Fourier transform (spatial frequency spectrum) and scanning it witha rotating spatial filter matched to the streak spectrum. The filter angle at maximum energy transmissiondetermines the streak direction and a second Fourier transform provides coordinate information. The designof the optical system is described and some initial experimental results are shown.IntroductionAn effective midcourse ballistic missile defense (BMD) system requires the ability to launch an intercep-tor toward an incoming threat at the earliest possible time in order to find and destroy it. A hominginterceptor must be capable of searching a large sky sector and detecting the presence of a threat whilediscriminating among numerous other objects. Although simple in concept, the search task requires an enor-mous amount of computing power and data storage capacity. The trend in sensor design indicates that improvedsensor capabilities for BMD systems can be expected to increase the data rate by several orders of magnitudeover that of present sensors. The ability to handle these high data rates is important for advanced BMDsystems, especially when size, space, and weight are limited, as they are aboard a homing interceptor.This paper presents some initial results obtained in a program funded by the U. S. Army's BMD AdvancedTechnology Center (BMDATC). The program objective is to evaluate the capabilities of optical data process-ing to serve as an on -board preprocessor for the large volume data outputs from mosaic optical sensor arrays.Two processing phases are being considered:

1 citations


Proceedings ArticleDOI
08 Dec 1977
TL;DR: In this article, a real-time digital compensation technique that corrects for the non-uniformities in both dark currents and responsivities of solid-state electro-optical imaging arrays is presented.
Abstract: Present solid-state infrared staring imagers are characterized by large element-to-element nonuniformities in both dark currents and responsivities. These nonuniformities result in "fixed pattern" noise which can exceed the amplitude of the desired signal by more than 500 times. For solid-state infrared staring imagers to be a viable alternative to other infrared imaging systems, real-time nonuniformity compensation must be developed. This paper presents a real-time digital compensation technique that corrects for the non-uniformities in both dark currents and responsivities of solid-state electro-optical imaging arrays. Experimental results yielded a measured net gain in the signal to fixed pattern noise ratio of 46 dB. Hardware is described and results demonstrated for a 32 by 32 CID (charge injection device) visible imaging array using a simulated infrared image and background. Basic MTI (moving target indication) and target correlation features as well as extrapolation to 128 by 128-element staring arrays are also discussed.

Journal ArticleDOI
TL;DR: In this paper, some new applications and the study of the use of sonar by bats are discussed. But the main focus is on the automatic plot extraction and data utilisation.
Abstract: The microwave antenna, the high-power microwave transmitter, pulse compression, the microwave receiver, moving target indication and the Doppler filter, the charge-coupled device in radar signal processing, automatic plot extraction and data utilisation, the Digilux interactive display, some new applications and the study of the use of sonar by bats are included

01 Jan 1977
TL;DR: In this paper, the authors present a method for designing optimal array correction patterns which, when used in conjunction with the primary receive pattern, minimize the effects of platform motion on the canceled clutter residue.
Abstract: Absstroct-Motion compensation techniques for coherent detection systems aboard a moving platform are discussed. Many radar and sonar systems are designed to detect moving targets within a volume of space and to reject returns from fiied objects. This can be achieved with some type of velocity (Doppler) filtering such as the moving target indicator (bl). When the detection system is on a moving platform, both temporal and spatial processing techniques are needed to maintain good system performance. This paper presents a method for designing optimal (LMS) array correction patterns which, when used in conjunction with the primary receive pattern, minimize the effects of platform motion on the canceled clutter residue.