Ground penetrating radar investigations of buildings and other man-made structures often require data collection along curvilinear interfaces having various radii of curvature and geometry. Data collected along non-pl...
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ISBN:
(纸本)0819457736
Ground penetrating radar investigations of buildings and other man-made structures often require data collection along curvilinear interfaces having various radii of curvature and geometry. Data collected along non-planar interfaces and containing multiple targets are often difficult to interpret without the application of migration. Migration is not commonly applied to surveys along non-planar interfaces because most published algorithms and available software assume data collection along planar interfaces. We provide a versatile imaging strategy that migrates data by using a kernel derived from the forward model. Modeled and measured data from columns are used to illustrate the utility of our imaging approach.
We present a procedure wherein unattended ground sensors (UGSs) that are not equipped with GPS can locate their own positions by transmitting pulses and receiving retransmitted pulses from UGSs that are equipped with ...
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ISBN:
(纸本)0819457736
We present a procedure wherein unattended ground sensors (UGSs) that are not equipped with GPS can locate their own positions by transmitting pulses and receiving retransmitted pulses from UGSs that are equipped with GPS. The payoff of this approach is reduced cost for the network of UGSs. We show through simulation that the implementation of this procedure locates the sensors that do not have GPS with sufficient accuracy for the network of UGS to detect and locate moving targets.
Long range radar (LRR) systems have made their way to middle class cars today, however due to limited sensor performance, almost only comfort functions have been realized yet. The most critical issue in most of today&...
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ISBN:
(纸本)2960055136
Long range radar (LRR) systems have made their way to middle class cars today, however due to limited sensor performance, almost only comfort functions have been realized yet. The most critical issue in most of today's LRRs is their lack in angular resolution and angular measurement quality. This topic is addressed by sensor manufacturers with the re-introduction of mechanical beam steering and research on phased array radar using digital beam forming. Data fusion will play an important role in next generation driver assistance functions so LRR design and interfaces must be prepared to provide raw data interfaces and non-application specific sensor designs.
作者：
Innocenti, RUSA
Res Lab Sensors & Electron Devices Directorate Adelphi MD 20783 USA
A need exists for greater situational awareness at the lower echelons of the Army. Radio Frequency (RF) sensors on small, lightweight Unmanned Aerial Vehicles (UAV) could provide lower echelon commanders with all-weat...
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ISBN:
(纸本)0819457736
A need exists for greater situational awareness at the lower echelons of the Army. Radio Frequency (RF) sensors on small, lightweight Unmanned Aerial Vehicles (UAV) could provide lower echelon commanders with all-weather reconnaissance, early warning, and target acquisition;however, the designs of these RF sensors are limited by the projected size and weight restrictions on the payload for a class 11 UAV. Consequently, these designs may favor combining simple RF sensor hardware with digital-signal processing (DSP) solutions over more sophisticated radar hardware. In this paper, we show the potential of simple, low cost RF sensors with hemispherical antenna coverage to overcome these limitations. The proposed RF sensor system uses DSP and pre-defined UAV flight patterns to detect and track moving targets from range and Doppler information. Our objective is to conceive and model a suite of software options that, by combining UAV flight patterns and processing algorithms, will be able to detect and track moving targets. In order to accomplish this, we are building a simulation that uses sensor models, target models, and battlefield dynamics to predict the targeting capabilities of the RF sensor system. We will use this simulation (1) to determine the tradeoffs between sensor complexity (and cost) and the military significance of the information gathered, and (2) to describe sensor error budgets for endgame lethality models.
Airborne synthetic aperture radar (SAR) imaging systems have reached a degree of accuracy and sophistication that requires the validity of the free-space approximation for radio-wave propagation to be questioned. Base...
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ISBN:
(纸本)0819457736
Airborne synthetic aperture radar (SAR) imaging systems have reached a degree of accuracy and sophistication that requires the validity of the free-space approximation for radio-wave propagation to be questioned. Based on the thin-lens approximation, a closed-form model for the focal length of a gravity wave-modulated refractive-index interface in the lower troposphere is developed. The model corroborates the suggestion that mesoscale, quasi-deterministic variations of the clear-air radio refractive-index field can cause diffraction patterns on the ground that are consistent with reflectivity artifacts occasionally seen in SAR images, particularly in those collected at long ranges, short wavelengths, and small grazing angles.
Effectiveness of modern weapon systems demands that it is important to distinguish between friends and foes as early as possible. radar signal based helicopter categorization is a challenging task for all types of rad...
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ISBN:
(纸本)0819457736
Effectiveness of modern weapon systems demands that it is important to distinguish between friends and foes as early as possible. radar signal based helicopter categorization is a challenging task for all types of radars. Airborne pulse Doppler radar with an appropriate digital signal processing unit has a good potential to perform categorization or even classification, providing that radar parameters are carefully fixed. Moreover, some information about the main rotor parameters of interesting helicopter types must also be known in advance. The idea of this paper is to present a helicopter categorization method, which is based on estimates of the main rotor blade tip velocity and the time interval between successive main rotor blade flashes. Both incoherent integration and conventional coherent integration play an important role in the new method. Moreover, a new edge detection algorithm is applied to coherently integrated signal. Simulations are performed in order to show the effectiveness of the method.
The results of numerical electromagnetic simulation and analysis of a set of positive-adaptive UAV radar signals are presented. These signals are simulated via the modeling of materials that enclose "building-typ...
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ISBN:
(纸本)0819457736
The results of numerical electromagnetic simulation and analysis of a set of positive-adaptive UAV radar signals are presented. These signals are simulated via the modeling of materials that enclose "building-type" structures with a series of connected dielectric materials. For example, windows, walls, and doors are each modeled separately by a combination of suitable material properties. Signals from objects that are embedded within these "building-type" structures are also simulated via the development and application of appropriate geometrical and materials models. Analysis of the resulting simulated "leakage signals" that penetrate the surfaces of these "building-type" structures and are backscattered from embedded objects within the indoor environment back to the simulated outdoor environment are presented. The results of a signal analysis are presented in two categories. The first set of results illustrates signal trends that can be exploited by "position-adaptive" mini-UAV's to isolate effective "leakage points" in "building-type" structures. The second set of results illustrate signal trends from embedded objects after a particular "position-adaptive" mini-UAV has converged to a "leakage point."
This paper presents a new technique able to detect extended targets (small ones and big ones) [1]., under very low signal to noise ratios (SNR) and signal to clutter ratios (SCR) with a high probability of detection a...
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ISBN:
(纸本)0780392450
This paper presents a new technique able to detect extended targets (small ones and big ones) [1]., under very low signal to noise ratios (SNR) and signal to clutter ratios (SCR) with a high probability of detection and a low probability of false alarm. The method is based on the calculation of some modified statistical descriptors [2]. and the peak plots [3], [4], from raw sensor image. The peak plots are extracted by means of the shift-and-convolution technique [5]. [6]. Experimental results are also presented demonstrating the quality of this technique. Experimental results have been obtained with ARIES radar [71, a surface marine and coast surveillance LFM-CW high resolution radar (HRR) [8] [9] developed by INDRA SISTEMAS S.A. in collaboration with the Technical University of Madrid. The Spanish Ministry of Defence has founded this research.
A compact dual mode seeker is under development at Diehl BGT Defence (DBD) addressing autonomous guidance, target detection and classification/identification for extended air defence (EAD) and ballistic missile defenc...
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ISBN:
(纸本)0819457760
A compact dual mode seeker is under development at Diehl BGT Defence (DBD) addressing autonomous guidance, target detection and classification/identification for extended air defence (EAD) and ballistic missile defence (BMD). The dual mode sensor consists of an imaging infrared sensor and an imaging LADAR sensor both in snapshot mode. This paper presents the concept of the dual mode sensor and shows the current development status. Critical components such as a compact laser source, fiber-array for image plane sampling, and wavelength selective infrared beam splitter are presented in detail. Single Spot and 3D-LADAR-measurements were performed with a seeker lab-setup to demonstrate the system.
In this paper C-band (similar to 5.75GHz), dual polarization, Doppler scatterometer is developed, for short distance remote sensing of water surface microwave reflective and spectrum characteristics simultaneous and c...
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ISBN:
(纸本)0819457736
In this paper C-band (similar to 5.75GHz), dual polarization, Doppler scatterometer is developed, for short distance remote sensing of water surface microwave reflective and spectrum characteristics simultaneous and coincident measurements, under laboratory-control conditions. Developed system will be set on a mobile bogie moving on the height of 6.5m along a stationary platform of 32m of length. It will allow carry out polarimetric (vv, vh, hh, hv), simultaneous and coincident microwave active measurements of pool water surface parameters at angles of incidence from the while of 0-40 degrees.
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