In support of the ARPA-sponsored Critical Mobile Targets program, Lincoln Laboratory has developed a complete, end-to-end, automatic target recognition (ATR) system using very high resolution (1 ft/spl times/1 ft), fu...
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In support of the ARPA-sponsored Critical Mobile Targets program, Lincoln Laboratory has developed a complete, end-to-end, automatic target recognition (ATR) system using very high resolution (1 ft/spl times/1 ft), fully polarimetric, Ka-band SAR data. Lincoln Laboratory has also developed ATR systems for reduced resolution (1 m/spl times/1 m) and single polarization data; performance comparisons (1 ft/spl times/1 ft versus 1 m/spl times/1 m and fully polarimetric versus single polarization) have been performed. There has been interest in the use of automatic target cueing (ATC) followed by ATR. In military operations, targets are often deployed in well-defined groups, such as tank companies. It is possible to exploit this information by developing algorithms to detect such groups of targets. Cueing algorithms identify potential target groups; then these areas can be revisited with a higher resolution sensor or these areas can be processed with more sophisticated algorithms (or both). This paper presents results from a joint ATC/ATR system that uses single polarization (HH) 1 m/spl times/1 m resolution data for both ATC and ATR; descriptions of the algorithms in the system are given and the performance is compared to the (1 ft/spl times/1 ft) very accurate resolution system run on the identical data set. The data used in this study consisted of 231 km/sup 2/ of 20 degree depression angle stripmap clutter from several areas in the northern United States; these data had varying amounts of cultural content from benign to severe.
There is growing interest in the United States in the protection of high value assets from aircraft intrusion. Aircraft technology has improved Helicopters can serve as an intruder transport, a highly mobile weapon pl...
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There is growing interest in the United States in the protection of high value assets from aircraft intrusion. Aircraft technology has improved Helicopters can serve as an intruder transport, a highly mobile weapon platform, and an escape vehicle after an intrusion has been committed. The helicopter can also serve as a transport for a high value material asset that may be stolen. Fixed wing aircraft are also a threat. The suicide mission to destroy an asset or generate adverse publicity is credible. If there is sufficient runway, the fixed wing aircraft can serve as a transport of intruders into a protected site, an intruder escape vehicle, or a transport for a stolen high value asset. The runway for a short take off and landing (STOL) aircraft used as intrusion vehicle can be any cleared area, including roadways only 100 meters in length with obstructions 20 meters high at the end. There may be existing, in place aircraft detection sensors near most sites that can be used to detect an aircraft's presence and provide early warning. If not, there is another family of sensors that can detect, track, and classify detected aircraft as fixed wing or helicopter. This second class of sensor can be installed if high resolution tracking of a target is required. The paper discusses the principles of aircraft detection, reviews some of the technology presently on the market for aircraft detection, and presents test data to show the ranges at which aircraft can be detected by these types of sensors.
This paper deals with the fusing of data from radar and imaging sensors at the dynamic level by generating a common state and observation model that relates the measurements to the common state vector. A key point whi...
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ISBN:
(纸本)0819415391
This paper deals with the fusing of data from radar and imaging sensors at the dynamic level by generating a common state and observation model that relates the measurements to the common state vector. A key point which is taken into account in the paper is the fact that a radar provides center-of-reflection measurements that may not correspond very well to the true target center, and as the target aspect changes, the center-of-reflection may vary about the true target center. For small targets at long range, this effect may be negligible, but for semi- extended or extended objects, the mismatch must be considered. In the approach developed in the paper, the radar center-of-reflection measurements are modeled in terms of random perturbations of unknown constant off-sets from the true target center in spherical coordinates. Estimate of these off-sets are used in an extended Kalman filter approach to target tracking using radar and imaging sensordata. The performance of the resulting tracking filter is evaluated via computer simulations.
One aspect of system performance assessment of an Over-The-Horizon-radar (OTHR) requires a meaningful comparison of radar tracking data (geographic, kinematic, etc) against external ground-truth data measuring these s...
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One aspect of system performance assessment of an Over-The-Horizon-radar (OTHR) requires a meaningful comparison of radar tracking data (geographic, kinematic, etc) against external ground-truth data measuring these same quantities. These external data may originate from multiple sources each exhibiting unique characteristics even though they may describe a common target. To perform a comparison, the ground-truth data must be associated with the corresponding radardata. In general, the amount of data generated by these systems precludes a manual association of truth and radardata;an automated method is required. This paper successfully demonstrates the application of an artificial intelligence technique employing fuzzy logic to this problem, using real tracking data obtained from Australia's Jindalee OTHR.
The need to understand the statistical and spectral characteristics of synthetic aperture radar (SAR) data prompted the analysis of ADTS SAR data. The analysis included statistical and spectral analyses, with an empha...
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ISBN:
(纸本)0819415340
The need to understand the statistical and spectral characteristics of synthetic aperture radar (SAR) data prompted the analysis of ADTS SAR data. The analysis included statistical and spectral analyses, with an emphasis on understanding the impact of the SAR processing on the scene properties. Several models were developed, including a SAR Processing model and a scene generating model which explicitly models the scene speckle. As a result, a documented and tested FORTRAN program is available for spectral analysis. The statistical and spectral characteristics form the basis of ongoing SAR modeling.
A cockpit revolution is in the making. Many of the much ballyhooed, much promised, but little delivered technologies of the 70's and 80's will finally come of age in the 90's just in time to complement the...
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A cockpit revolution is in the making. Many of the much ballyhooed, much promised, but little delivered technologies of the 70's and 80's will finally come of age in the 90's just in time to complement the data explosion coming from sensor and processing advances. Technologies such as helmet systems, large flat panel displays, speech recognition, color graphics, decision aiding and stereopsis, are simultaneously reaching technology maturities that promise big payoffs for the third generation cockpit and beyond. The first generation cockpit used round dials to help the pilot keep the airplane flying right side up. The second generation cockpits used Multifunction Displays and the HUD to interface the pilot with sensors and weapons. What might the third generation cockpit look like? How might it integrate many of these technologies to simplify the pilot's life and most of all: what is the payoff?. This paper will examine tactical cockpit problems, the technologies needed to solve them and recommend three generations of solutions.
The radarSAT mission utilizes a Synthetic Aperture radar (SAR) system to produce images representing terrain radiometric backscatter levels. The SAR system consists of Space and Ground Segments. The Space Segment is a...
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One of the most important aspects in the navigation of ALV is computer vision or machine vision. Usually, it is achieved by using multisensor fusion technology. As we know, laser radar is a typical sensor in this proj...
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ISBN:
(纸本)0819415952
One of the most important aspects in the navigation of ALV is computer vision or machine vision. Usually, it is achieved by using multisensor fusion technology. As we know, laser radar is a typical sensor in this project, especially in the situation that there is an obstacle in a road. It is often effective to describe the relationship between road and obstacle by using height matrix from range data. However, when the front view is more complicated, such as a wall or a building on which exists a hole or a corridor big enough for ALV to go through, the above method may not be well done. For this reason, we propose a novel approach by using two matrixes from the range data to solve the problem. The main idea is that from the range data we figure out two matrixes, one is the height matrix, representing the height of the object from the horizontal plane, the other is the depth matrix representing the depth of the object from the laser radar vertical plane. By using the information of both height and depth, we can understand the front environment more precise and better.
With the increased availability of coherent wideband radars, there has been a renewed interest in radar target recognition. A large bandwidth gives high resolution in range which means target recognition may be possib...
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In this paper we present a new maximum likelihood array signal processing algorithm that uses self-calibration and the Total Least Squares (TLS) technique for improved direction finding when the sensor (or antenna) po...
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ISBN:
(纸本)0780314395
In this paper we present a new maximum likelihood array signal processing algorithm that uses self-calibration and the Total Least Squares (TLS) technique for improved direction finding when the sensor (or antenna) positions are not known exactly. The TLS method is a generalized data fitting method that is appropriate for cases when the system model contains error or is not known. In order to apply TLS techniques to array signal processing, we propose Constrained-TLS (C-TLS) and show that the solution can be represented by combining the constraint and the Least Squares (LS) approach. The algorithm performs calibration and direction estimation iteratively using both TLS and C-TLS techniques.
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