We investigate the application of the kernel-based generalized discriminant analysis (GDA) approach to the recognition of infrared face images collected using a low-resolution uncooled IR camera. Results show that a low-cost, low-resolution IR camera combined with an efficient classifier is a usable tool in uncooled IR face recognition applications, and that best GDA-based recognition performance improves over that obtained with the fisherface approach by 3.96 percentage points, from 94.59% to 98.55%, on the data considered. This study also investigates the effects the number of projection vectors used in the GDA step, the kernel expression, and the specific distance type have on recognition performance. Results show the Mahalanobis angular distance to be the best choice, and that the recognizer computational load may be reduced by decreasing the number of eigenvectors selected in the GDA projection step without significant impact on recognition performance.
Recent advances in uncooled infrared technology have resulted in thermal imagers with resolution approaching that of cooled counterparts at a significantly lower cost. We investigate the application of linear classification schemes to a database consisting of 420 images collected from 14 adult subjects using an uncooled infrared camera under indoor controlled conditions. Results show that the linear discriminant approach (LDA) leads to the best classification performances (99.3%), while the best principal component analysis (PCA)-based scheme leads to an accuracy of 91.33%. Results also show that PCA-based classification scheme performance improves by removing the top three eigenvectors, associated with the three largest eigenvalues, from consideration in the generation of the PCA projection matrix for the small database considered in this study, as was noted in visible imaging face recognition studies.
Improved situational awareness is a primary goal for the Objective Force. Knowing where the enemy is and what are the threats to his troops provides the commander with the information he needs to plan his mission and provide his forces with maximum protection from the variety of threats that are present on the battlefield.
Sensors play an important role in providing critical information to enhance situational awareness. The sensors that are used on the battlefield include, among others, seismic, acoustic, and cameras in different spectral ranges of the electro-magnetic spectrum. These sensors help track enemy movement and serve as part of an intrusion detection system. Characteristically these sensors are relatively cheap and easy to deploy.
Chemical and biological agent detection is currently relegated to sensors that are specifically designed to detect these agents. Many of these sensors are collocated with the troops. By the time alarm is sounded the troops have already been exposed to the agent. In addition, battlefield contaminants frequently interfere with the performance of these sensors and result in false alarms. Since operating in a contaminated environment requires the troops to don protective garments that interfere with their performance we need to reduce false alarms to an absolute minimum.
The Edgewood Chemical and Biological Center (ECBC) is currently conducting a study to examine the possibility of detecting chemical and biological weapons as soon as they are deployed. For that purpose we conducted a field test in which the acoustic, seismic and electro-magnetic signatures of conventional and simulated chemical / biological artillery 155mm artillery shells were recorded by an array of corresponding sensors. Initial examination of the data shows a distinct differences in the signatures of these weapons.
In this paper we will provide detailed description of the test procedures. We will describe the various sensors used and describe the differences in the signatures generated by the conventional and the (simulated) chemical rounds. This paper will be followed by other papers that will provide more details information gained by the various sensors and describe how fusing the data enhance the reliability of the CB detection process.
The threat of chemical and biological weapons is a serious problem and the ability to determine if an incoming artillery round contains high explosives or a chemical/biological agent is valuable information to anyone on the battlefield. Early detection of a chemical or biological agent provides the soldier with more time to respond to the threat. Information about the round type and location can be obtained from acoustic and seismic sensors and fused with information from radars, infrared and video cameras, and meteorological sensors to identify the round type quickly after detonation. This paper will describe the work with ground based acoustic and seismic sensors to discriminate between round types in a program sponsored by the Soldier Biological and Chemical Command.
In this paper we use a non-stationary approach and analyze ultra-wideband (UWB) radar data using time-frequency and time-scale transformations. The time-frequency transformations considered are the Short-Time Fourier Transform (STFT), the Wigner-Ville Distribution (WD), the Instantaneous Power Spectrum (IPS), and the ZAM transform. Two discrete implementations of the Wavelet Transform (DWT) are also investigated: the decimated A- trous algorithm proposed by Holschneider et al, which uses non-orthogonal wavelets; and the Mallat algorithm, which employs orthogonal wavelets. The transients under study are UWB radar returns from a boat (with and without corner reflector) in the presence of sea clutter, multipath, and radio frequency interferences (RFI). Results show that all time-frequency and time-scale transforms clearly detect the transient radar returns corresponding to the boat with a corner reflector. However, as the radar cross section of the target decreases (boat without a corner reflector), results change drastically as the RFI component dominates the signal. Simulations show that the Instantaneous Power Spectrum may be better adapted for localizing the transient among the time-frequency techniques studied. The decimated A-trous algorithm has the best time resolution of the techniques studied as the return appears better localized in the scalogram.
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