A multi-dimensional laser radarsensor is developed to perform three-dimensional imaging polarimetry. The imaging polarimeter is an extension of the existing, well-developed Streak Tube Imaging Lidar (STIL) technology...
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ISBN:
(纸本)0819440728
A multi-dimensional laser radarsensor is developed to perform three-dimensional imaging polarimetry. The imaging polarimeter is an extension of the existing, well-developed Streak Tube Imaging Lidar (STIL) technology. With polarization optics added to the transceiver system, simultaneous capture of 3D high-resolution polarimetric and reflectance imagery is achieved over wide fields of view. Laboratory and field experiments exhibit the capability of the imaging polarimeter for enhancing clutter reduction, image segmentation, and target discrimination for low contrast and camouflaged targets.
This paper evaluates five potential feature selection methods in the application of remote sensing. The five methods include the sequential forward floating selection, the joint pair approach, band selection based on ...
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ISBN:
(纸本)081944281X
This paper evaluates five potential feature selection methods in the application of remote sensing. The five methods include the sequential forward floating selection, the joint pair approach, band selection based on variance, the principal component transform, and the visual-based selection. Optical-sensor image and synthetic aperture radar image are used for experiments. Several recommendations are made based on this study. For optical-sensor images, the five feature selection methods: sequential forward floating selection, joint pair, band selection, principal component transform, and visual-based selection could have about the same classification accuracy using two to five selected features. The case study has shown that the sequential forward floating selection is the best feature selection method for both optical and synthetic aperture radar feature image selection, followed by the joint pair (for two-feature selection), visual-based selection, band selection, and principal component transform. For band L and band X synthetic aperture radar feature images, entropy, homogeneity, inverse difference moment, and maximum probability, East to West and West to East semivariogram, the local mean value, maximum, and minimum are the best features of the co-occurrence matrix model, semivariogram model, and local statistic model. For Landsat TM images band 7, 4, 5, 3, 1, and 2 are significant feature images. Applying the sequential forward floating selection to select two to five features from the potential features can obtain classification accuracy greater than 90%.
The background is in the state of the art, in airborne radars that detect moving targets in the presence of ground clutter and measure their range, radial velocity and azimuth, consists of the following: Delay line ca...
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ISBN:
(纸本)0819440698
The background is in the state of the art, in airborne radars that detect moving targets in the presence of ground clutter and measure their range, radial velocity and azimuth, consists of the following: Delay line cancellor Systems Monopulse Systems Two subarray DPCA radar Three Subarray DPCA radar The Delay Line cancellor and the Monopulse systems, if the moving target is in the presence of main beam clutter the mover cannot be detected and therefore cannot measure its velocity. The DPCA radar with three subarrays attains the objective of detecting a moving target in the presence of clutter and measuring its radial velocity and azimuth position but takes three subarrays (more hardware and processing). The DPCA radar with two subarrays detects a moving targets but the precise angle and radial velocity cannot be determined in the presence of clutter. This is the reason for the three-subarray antenna to attain the precise velocity and azimuth. This paper is unique in that it will attain the precise angle and radial velocity of the detected moving target and also will have additional features such as increased accuracy, reduced dwell time and processing. Since the three subarrays. DPCA radar system above has an additional degree of freedom, additional information is required to obtain the same or better results with the two-subarray system. This manuscript develops the mathematical basis and the physical radar principles and computer simulation results which are the basis for the three (3) techniques developed. The three techniques developed to attain the objective are unique and based on extensive mathematical development and computer simulation of radar principles and employ real radardata. The object of this paper is to further process the radardata from two synthetic arrays and determine very accurately the range, relative radial velocity and angular position of the target (within the resolution of a doppler bin or better). The target may or not be in the presen
The paper describes the design of a multi-sensor ultra wideband GPR front-end suitable for subsurface imaging with resolution sufficient for antipersonnel mine recognition. The front-end comprises two sensors: a multi...
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The Air Force Research Laboratory's sensor Directorate is developing the next step in target recognition, a continuous identification capability. This capability consists of a wide range of algorithms, sensor mode...
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ISBN:
(纸本)0819440779
The Air Force Research Laboratory's sensor Directorate is developing the next step in target recognition, a continuous identification capability. This capability consists of a wide range of algorithms, sensor modes and technologies that work in concert to contribute to the overall goal of identification of moving as well as stationary targets. Three major pieces of this emerging capability are stationary identification, correlation of this information with tracks and the moving target recognition technologies. Although a brief discussion of each of these pieces will be provided in this paper, the concentration will be on the actual algorithms and technologies of the moving target recognition exploiting High Range Resolution (HRR) radar mode and how this complements Ground Moving Target Indication (GMTI) tracking and Synthetic Aperture radar (SAR) Automatic Target Recognition (ATR). This paper will expand on the overall continuous ID vision, work performed under several efforts, new sources of HRR data, and how this data will push the state of the art. The advantages of continuous ID should be obvious to the warfighter in many dimensions. As a command and control structure it is very difficult to identify and target time critical targets especially when the identification process is limited to stationary targets. These technologies will provide a wider range of targeting options so the enemy has no sanctuary in moving, setting up and in hiding.
In order to improve the tracking performance of sensors, this paper addresses the issue of optimal state estimation in a hybrid multisensordata fusion system with feedback information for similar and dissimilar synch...
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ISBN:
(纸本)0780370007
In order to improve the tracking performance of sensors, this paper addresses the issue of optimal state estimation in a hybrid multisensordata fusion system with feedback information for similar and dissimilar synchronous sensors. In this system where a part of sensors process their data locally to produce local tracks, another part of sensors only provide detection reports, these tracks and detection reports are communicated to a central site where track fusion and state estimation are performed. Then the fusion results are return to some sensors, so that the tracking performance of sensors might be improved.
A cw CO2 Doppler lidar was modified for an airborne test of the principle of the true-airspeed sensor. During two flights in April 2000 the system was tested together with the wind sensor in the nose-boom of the resea...
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ISBN:
(纸本)0819440728
A cw CO2 Doppler lidar was modified for an airborne test of the principle of the true-airspeed sensor. During two flights in April 2000 the system was tested together with the wind sensor in the nose-boom of the research aircraft. The results are: there is an excellent correlation between the LOS components of the Doppler lidar and of the aircraft sensor. there is no dropout of data also in very cleen regions of the atmosphere (above 10 km). the Doppler sensor can also be used as an aerosol particle counter (in number densoity and with some indication of the size). A virtual instrument was used to design the sensor and was modified after the flight. It can be used to design a more compact fiber sensor.
Law enforcement and emergency services all face the difficult task of determining the locations of people within a building. A handheld radar able to detect motion through walls and other obstructions has been develop...
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ISBN:
(纸本)0819440698
Law enforcement and emergency services all face the difficult task of determining the locations of people within a building. A handheld radar able to detect motion through walls and other obstructions has been developed to fill this need. This paper describes the attributes and difficulties of the radar design and includes test results of the radar's performance. This discussion begins by summarizing key user requirements and the electromagnetic losses of typical building materials. Ultra-wideband (UWB) short pulse radars are well suited for a handheld sensor primarily because of their inherit time isolation in high clutter environments and their capability to achieve high resolution at low spectral center frequencies. There are also constraints that complicate the system design. Using a technique referred to as time-modulation allows the radars to reject range ambiguities and enhances electromagnetic compatibility with similar radars and ambient systems. An outline of the specifications of the radar developed and a process diagram on how it generates a motion map showing range and direction of the people moving within structures is included. Images are then presented to illustrate its performance. The images include adults, child, and a dog. The test results also include data showing the radar's performance through a variety of building materials.
An imaging "radarometer" mode integrates a radar with a radiometer in a manner which allows simultaneous use of a common imaging antenna. The goal of this research effort was the design of a MMW camera capab...
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ISBN:
(纸本)081944068X
An imaging "radarometer" mode integrates a radar with a radiometer in a manner which allows simultaneous use of a common imaging antenna. The goal of this research effort was the design of a MMW camera capable of obtaining simultaneous passive and active airborne images, in the radarometer mode. An Engineering Test Unit (ETU) was assembled to verify the design of an Engineering Model and to determine if any significant design changes were needed. ETU flight test data is presented and discussed in terms of sensor system capabilities and the Engineering Model design approach.
The CloudSat Mission is a new international satellite mission to acquire a global data set of vertical atmospheric cloud structure and its variability. Such data set is expected to provide crucial input to the studies...
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The CloudSat Mission is a new international satellite mission to acquire a global data set of vertical atmospheric cloud structure and its variability. Such data set is expected to provide crucial input to the studies of cloud physics, radiation budget, water distribution in the atmosphere, and to the numerical weather prediction models. The key science instrument aboard the CloudSat satellite is the Cloud Profiling radar (CPR). CPR is a 94-GHz nadir-looking radar that measures the power backscattered by clouds as a function of distance from the radar. This sensor is expected to provide cloud measurements at a 500-m vertical resolution and a 1.5-km horizontal resolution. CPR will operate in a short-pulse mode and will yield measurements at a minimum detectable sensitivity of-28 dBZ. In this paper, we will present the system design and the expected performance of this instrument, as well as the state-of-the art millimeter-wave technologies employed by this instrument.
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