James Jackman

Detection and classification of stress using thermal imaging technique

This paper reports how Electro-Optics (EO) technologies such as thermal and hyperspectral [1-3] imaging methods can be used for the detection of stress remotely. Emotional or physical stresses induce a surge of adrenaline in the blood stream under the command of the sympathetic nerve system, which, cannot be suppressed by training. The onset of this alleviated level of adrenaline triggers a number of physiological chain reactions in the body, such as dilation of pupil and an increased feed of blood to muscles etc. The capture of physiological responses, specifically the increase of blood volume to pupil, have been reported by Pavlidiss pioneer thermal imaging work [4-7] who has shown a remarkable increase of skin temperature in the periorbital region at the onset of stress. Our data has shown that other areas such as the forehead, neck and cheek also exhibit alleviated skin temperatures dependent on the types of stressors. Our result has also observed very similar thermal patterns due to physical exercising, to the one that induced by other physical stressors, apparently in contradiction to Pavlidiss work [8]. Furthermore, we have found patches of alleviated temperature regions in the forehead forming patterns characteristic to the types of stressors, dependent on whether they are physical or emotional in origin. These stress induced thermal patterns have been seen to be quite distinct to the one resulting from having high fever.

Illumination invariance and shadow compensation via spectro-polarimetry technique

Abstract. A major problem for obtaining target reflectance via hyperspectral imaging systems is the presence of illumination and shadow effects. These factors are common artefacts, especially when dealing with a hyperspectral imaging system that has sensors in the visible to near infrared region. This region is known to have highly scattered and diffuse radiance that can modify the energy recorded by the imaging system. A shadow effect will lower the target reflectance values due to the small radiant energy impinging on the target surface. Combined with illumination artefacts, such as diffuse scattering from the surrounding targets, background or environment, the shape of the shadowed target reflectance will be altered. We propose a new method to compensate for illumination and shadow effects on hyperspectral imageries by using a polarization technique. This technique, called spectro-polarimetry, estimates the direct and diffuse irradiance based on two images taken with and without a polarizer. The method is then evaluated using a spectral similarity measure, angle and distance metric. The results of indoor and outdoor tests have shown that using the spectro-polarimetry technique can improve the spectral constancy between shadow and full illumination spectra.

Countermeasure effectiveness against a man-portable air-defense system containing a two-color spinscan infrared seeker

Man-portable air-defense (MANPAD) systems have developed sophisticated counter-countermeasures (CCM) to try and defeat any expendable countermeasure that is deployed by an aircraft. One of these is a seeker that is able to detect in two different parts of the electromagnetic spectrum. Termed two-color, the seeker can compare the emissions from the target and a countermeasure in different wavebands and reject the countermeasure. In this paper we describe the modeling process of a two-color infrared seeker using COUNTERSIM, a missile engagement and countermeasure software simulation tool. First, the simulations model a MANPAD with a two-color CCM which is fired against a fast jet model and a transport aircraft model releasing reactive countermeasures. This is then compared to when the aircraft releases countermeasures throughout an engagement up to the hit point to investigate the optimum flare firing time. The results show that the release time of expendable decoys as a countermeasure against a MANPAD with a two-color CCM is critical.

Remote sensing of stress using electro-optics imaging technique

Emotional or physical stresses induce a surge of adrenaline in the blood stream under the command of the sympathetic nerve system, which, cannot be suppressed by training. The onset of this alleviated level of adrenaline triggers a number of physiological chain reactions in the body, such as dilation of pupil and an increased feed of blood to muscles etc. This paper reports for the first time how Electro-Optics (EO) technologies such as hyperspectral [1,2] and thermal imaging[3] methods can be used for the detection of stress remotely. Preliminary result using hyperspectral imaging technique has shown a positive identification of stress through an elevation of haemoglobin oxygenation saturation level in the facial region, and the effect is seen more prominently for the physical stressor than the emotional one. However, all results presented so far in this work have been interpreted together with the base line information as the reference point, and that really has limited the overall usefulness of the developing technology. The present result has highlighted this drawback and it prompts for the need of a quantitative assessment of the oxygenation saturation and to correlate it directly with the stress level as the top priority of the next stage of research.

The Effect of Pre-emptive Flare Deployment on First Generation Man-Portable Air-Defence (MANPAD) Systems:

Early generation Man-Portable Air-Defence (MANPAD) systems pose a significant threat to all types of aircraft. The need to develop successful countermeasures to this threat is ever more important with their worldwide proliferation. In this paper we discuss the use of CounterSim, a missile engagement and countermeasure simulation software tool, to gain a detailed understanding of the factors affecting an engagement outcome. The work starts by analysing simple engagements of a first generation MANPAD against a fast jet with no countermeasures being employed. From this set of base runs individual engagements are chosen to analyse in further detail. At each time interval in the simulation the aircraft and missile velocities are used to calculate a projected point of closest approach. This is then compared with the simulated impact point and the difference is defined as the projected miss distance, Δd. Features of plots of Δd are investigated to gain insights into the potential countermeasure capability. Finally, pre-emptive countermeasures are tested by firing two flares at the start of the simulation and then a timed sequence of flares.

Modelling a man-portable air-defence (MANPAD) system with a conical scan two-colour infrared (IR) seeker

The use of flares of flares against 1st and 2nd generation man-portable air-defence (MANPAD) systems proved to be very effective. This naturally led to the development of counter-countermeasures (CCM) that could be incorporated into the MANPADs infrared (IR) seeker. One possible CCM is two-colour where the seeker detects in two separate IR bands. It is designed to exploit the different spectral characteristics of the target and flare. In this paper we describe the modelling process of a two-colour conical scan (conscan) IR seeker using CounterSim, a missile engagement and countermeasure simulation software tool developed by Chemring Countermeasures Ltd. It starts by explaining the signal processing needed to be able to reject the flare and track the target. The MANPAD model is then used in an engagement with a fast jet model and a transport aircraft model. Flares are first deployed reactively then released throughout an engagement to investigate the effect of flare release time and the viability of pre-emptive countermeasures.

A biological cortex like target recognition and tracking in cluttered background

This paper reports how objects in street scenes, such as pedestrians and cars, can be spotted, recognised and then subsequently tracked in cluttered background using a cortex like vision approach. Unlike the conventional pixel based machine vision, tracking is achieved by recognition of the target implemented in neuromorphic ways. In this preliminary study the region of interest (ROI) of the image is spotted according to the salience and relevance of the scene and subsequently target recognition and tracking of the object in the ROI have been performed using a mixture of feed forward cortex like neuromorphic algorithms together with statistical classifier & tracker. Object recognitions for four categories (bike, people, car & background) using only one set of ventral visual like features have achieved a max of ~70% accuracy and the present system is quite effective for tracking prominent objects relatively independent of background types. The extension of the present achievement to improve the recognition accuracy as well as the identification of occluded objects from a crowd formulates the next stage of work.

Colour invariant target recognition in multiple camera CCTV surveillance

People tracking in crowded scene have been a popular, and at the same time a very difficult topic in computer vision. It is mainly because of the difficulty for the acquisition of intrinsic signatures of targets from a single view of the scene. Many factors, such as variable illumination conditions and viewing angles, will induce illusive modification of intrinsic signatures of targets. The objective of this paper is to verify if colour constancy (CC) approach really helps people tracking in CCTV network system. We have testified a number of CC algorithms together with various colour descriptors, to assess the efficiencies of people recognitions from multi-camera i-LIDS data set via receiver operation characteristics (ROC). It is found that when CC is applied together with some form of colour restoration mechanisms such as colour transfer, it does improve people recognition by at least a factor of 2. An elementary luminance based CC coupled with a pixel based colour transfer algorithm have been developed and it is reported in this paper.

Effect of payload size on pre-emptive flare countermeasure against man-portable air-defence (MANPAD) system

Military aircraft face a serious threat from early generation Man-Portable Air-Defence (MANPAD) systems. Robust countermeasures have to be used to counteract this threat. Most commonly these are used after the threat has been launched and detected. The ideal solution is to defeat the system pre-emptively before the missile is launched. One way to achieve this is to fire pre-emptive flares giving the MANPAD another hot source to track and lock-on to. However, use of pre-emptive flares can quickly deplete the flare magazines limiting the mission time and the area in which the aircraft will be protected. In this paper we discuss the use of CounterSim, a missile engagement and countermeasure simulation software tool, to investigate what effect the flare output and burn time may have on the effectiveness of preemptive countermeasures. The first set of simulations looks at a flare of full intensity and burn time pre-emptively released at the beginning of the simulations. Then, flares of reduced intensity and reduced burn time are used. In a second set of simulations the pre-emptive flare release time is investigated by delaying the firing up to one second from the beginning of the simulation.

Effect of pre-emptive flares on Man-Portable Air-Defence (MANPAD) systems with a track angle bias counter-countermeasure (CCM)

Man-Portable Air-Defence (MANPAD) systems can employ a range of counter-countermeasures (CCM) to reject expendable IR decoys. Three hypothetical MANPAD models are based on reticle types and CCM features that may be found in 1st and 2nd generation MANPADs. These are used in simulations to estimate the probability of escaping hit (PEH) when no IR decoys are used, when IR decoys are deployed reactively and when decoys are deployed preemptively. These cases are simulated for seekers with no CCM and with a track angle bias CCM. The results confirm that the rise rate CCM significantly reduces the PEH when IR decoys are used reactively. The use of pre-emptive flares timed to deploy at or about the time when the seeker is uncaged increases the PEH significantly. A more detailed investigation of the effects of aircraft aspect angle and flare timing on miss distance was carried out to examine the effects of the CCM compared with no CCM. With the aircraft at an altitude of 1000m and a range of 2km there is a critical period in which a flare needs to be released in order to achieve a significant miss distance when the CCM is in use. The conical scan seeker used with the track angle bias CCM was the most effective combination requiring the shortest time during which the flare had to be deployed. Further simulations at longer ranges and different aircraft azimuth angles showed that there is a time window that is range dependant during which pre-emptive decoys are fully effective independently of the aircraft azimuth or threat direction.