<title>Improved landmine detection capability (ILDC): systematic approach to the detection of buried mines using passive IR imaging</title>

Abstract

In order to reduce the serious problem associated with the mining of important supply/communication roads by hostile parties during peacekeeping operations, the Canadian Department of National Defence has recently begun the development of a multi-sensor teleoperated mine detection vehicle, the Improved Landmine Detection Capability (ILDC) . One sensor identified as a serious candidate for that project is a passive IR camera. In the past, many organizations have assessed the efficiency of this technique of detection and reported widely fluctuating results. It is believed that the main reason for these fluctuations is associated with the ad hoc interpretations used by different researchers. In this paper, a more systematic analysis is presented which takes into account variables such as time of the day, time of the year, weather conditions, type of road and many others. A working model is proposed in order to facilitate the prediction of the JR signature of the buried land-mines and is compared with data acquired from multiple trials. These trials were done with live mines (without fuzes) and surrogates buried in different types of road (packed gravel and sand) and during different times of the day and different times of the year.Jn the last 15 years, with the increase of peacekeeping activities in countries decimated by civil wars and other social disorders, the interest for mine detection and clearance has become increasingly important. To support the international effort to solve this critical problem, the Canadian Department of National Defence (DND) has put together a team of experts to design and build a multi-sensor remotely operated mine detection vehicle operating primarily on roads, the Improved Landmine Detection Capability (ILDC). One critical sensor of this vehicle is a passive JR camera. From recent work published by many organizations (RECON/OPTICAL Inc.,"2 Wackenhut Advanced Technology Corp.,3 \VES,4 ERIM,5 LLNL6'7), it is well accepted that JR technology has good capabilities to detect metal-free buried mines. However, one drawback of this technique is its performance dependency on environmental conditions (time of day, time of year, weather conditions, type of road,...). In this document, the author proposes a methodology well adapted to monitor and anticipate the fluctuations in the efficiency of JR technology in detecting buried mines.We will first describe two models (one being a simplified version of the other) which interpret quantitatively the thermal mechanisms involved in the formation of the JR signature of buried mines. Subsequently, the validity of the quantitative parameters identified by these models is tested experimentally during trials designed especially to reproduce real operating scenarios. Throughout the trials, special attention has been given to the evaluation of the limitations associated with the use of these quantitative parameters. Then, the experimental results are O-8794-2146-4/96/$6.OO SPIEVo!. 2765/489 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/...

Analysis of a thermal imaging method for landmine detection, using infrared heating of the sand surface

“…These papers indicate that a typical value for both the characteristic dimension of the discontinuity and its depth beneath the surface will be less than 0.01 m. For the discontinuities detected, the ratio of depth to characteristic dimension rarely exceeds 0.7. Maierhofer et al [3] also used this technique to detect voids in a concrete block where both the characteristic dimension and burial depth of the discontinuity were an order of magnitude greater than those described by Almond et al When this procedure is applied to the detection of landmines, the discontinuity within the homogeneous soil is taken to be either the complete landmine [4,5], an internal component of the mine such as the gas space used to house its firing mechanism [6,7] or possibly even the disturbed soil created when the mine was buried [8]. Most of these discontinuities have a similar location: the upper surface of the mine.…”

“…Most of these discontinuities have a similar location: the upper surface of the mine. The heating process adopted for mine detection schemes include the surface heating of the soil using infrared lamps [4,9], solar energy [6,8,10,11] and the volumetric heating of the soil by microwave energy [7,12]. Each of these heating processes introduces features which can assist or limit the overall detection process.…”

“…Each of these heating processes introduces features which can assist or limit the overall detection process. In addition the use of pulsed thermography to detect landmines has been widely investigated both analytically [5,6,10] and experimentally [4,[7][8][9]13].…”

Context-dependent fusion with application to landmine detection.

“…Using the update rules in (71) and (72), it can be shown that the weights need to be updated using: (80) where…”

A generic framework for context-dependent fusion with application to landmine detection.

“…When it is due primarily to the disturbed soil layer above and around the mine (resulting from the burying operation), one speaks of a surface effect, which can be detectable for some time (say weeks) after burial and enhances the mine's signature. A good explanation of the various thermal mechanisms affecting the surface temperature contrast can be found in [109].…”