Hamburg, Univ., Diss., 2001. / Computerdatei im Fernzugriff.

Hamburg, Univ., Diss., 2001. / Computerdatei im Fernzugriff.

Darmstadt, Techn. Universiẗat, Diss., 2005.

Hamburg, University, Diss., 2001.

Zugl.: Hamburg, Univ., Diss., 2001 / Hergestellt on demand

Antipersonnel (AP) landmines are cheap and simple weapons used in warfare and other armed conflicts. The most effective and accepted form of landmine clearance is by manual demining, but this method is slow, laborious, costly and hazardous. The use of mechanical devices such as chain flails for landmine neutralization and/or area reduction has the potential of greatly aiding landmine clearance. However, mechanical clearance methods have not been fully accepted in the landmine clearance community due to a lack of knowledge and scientific data the actual soil-tool interaction and the landmine clearance effectiveness. <p>The research objective was to develop a mechanical device for the neutralization of AP landmines. The device was to deliver sufficient force to produce adequate ground deflection for detonation of typical antipersonnel landmines at depths up to 200 mm. Other design parameters included design simplicity, high durability with low and ease of maintenance and flexible operation. <p>A design matrix was employed to select an appropriate design for further analysis, resulting in preliminary testing and evaluation of off the shelf mechanisms, namely a Tamper and a Jackhammer. Key parameters included interaction pressure, sensor deflection and duty cycle. It was concluded that a tamper design resulted in superior demining capabilities. A final testing phase was designed and conducted to further research the effectiveness of the device and to determine optimal operational parameters between two shoe sizes and the number of pass applications. A test rig was designed and fabricated to attach the tamper system onto the Terra Mechanics Rig for test automation. Test results revealed that the small tamper shoe configuration performed better than a larger shoe, but only marginally so. Test results also indicated a two pass operation was optimal and that the proper shoe configuration is dependent on the demining environment. Furthermore, the large magnitudes of interaction pressure, deflection sensor displacement and total impulse indicate that the tamper system is capable of detonating AP landmines at depths of up to 200 mm.

Antipersonnel (AP) landmines are cheap and simple weapons used in warfare and other armed conflicts. The most effective and accepted form of landmine clearance is by manual demining, but this method is slow, laborious, costly and hazardous. The use of mechanical devices such as chain flails for landmine neutralization and/or area reduction has the potential of greatly aiding landmine clearance. However, mechanical clearance methods have not been fully accepted in the landmine clearance community due to a lack of knowledge and scientific data the actual soil-tool interaction and the landmine clearance effectiveness. <p>The research objective was to develop a mechanical device for the neutralization of AP landmines. The device was to deliver sufficient force to produce adequate ground deflection for detonation of typical antipersonnel landmines at depths up to 200 mm. Other design parameters included design simplicity, high durability with low and ease of maintenance and flexible operation. <p>A design matrix was employed to select an appropriate design for further analysis, resulting in preliminary testing and evaluation of off the shelf mechanisms, namely a Tamper and a Jackhammer. Key parameters included interaction pressure, sensor deflection and duty cycle. It was concluded that a tamper design resulted in superior demining capabilities. A final testing phase was designed and conducted to further research the effectiveness of the device and to determine optimal operational parameters between two shoe sizes and the number of pass applications. A test rig was designed and fabricated to attach the tamper system onto the Terra Mechanics Rig for test automation. Test results revealed that the small tamper shoe configuration performed better than a larger shoe, but only marginally so. Test results also indicated a two pass operation was optimal and that the proper shoe configuration is dependent on the demining environment. Furthermore, the large magnitudes of interaction pressure, deflection sensor displacement and total impulse indicate that the tamper system is capable of detonating AP landmines at depths of up to 200 mm.

Zugl.: London, Univ., Diss., 2006

The following abstract is for a thesis submitted to the University of Manchester for the degree of Doctor in Philosophy by Omar AbdelRehim AbdelKerim in 2015.Anti-personnel (AP) mines remain a global problem that affects communities around the world, with 110 million active landmines still present. Landmines are a particularly callous and indiscriminate type of weapon detonating irrespective of presence of an enemy soldier or a child. Their devastating effect on communities has led to their ban through the 1997 Mine Ban Treaty. Current detectors used for mine clearance operations have an impeding weakness that has prompted this research; metal detectors used in humanitarian demining suffer from a high False Alarm Rate (FAR) prompting regular excavation of metallic clutter. The research presented aims to develop a detector capable of discriminating between metallic clutter and mines through the use of the magnetic polarizability dyadic tensor to reduce FARs, increase demining efficiency and improve deminer’s safety. A measurement apparatus was designed and constructed to perform spectroscopic magnetic measurements of small symmetrical metallic objects and produce for the first time unscaled accurate tensor values. The tensors deduced from the measurements were validated against analytical and simulated results and were found to be within 5% of measured tensors. The tensors of minimum metal AP mine surrogates and metallic clutter of symmetrical shape were measured and formed part of a tensor library to be used later by future research. This is in addition to a set of un-circulated US coinage which could be used as a calibration metric and a comparison piece for future work in this area. A detailed description of the coil design and manufacturing process is presented to develop a coil array capable of inverting buried metallic object tensors. The selection criterion was poised to identify an array that was best suited to perform the correct measurements in order to invert to an accurate tensor. The manufactured coil exhibited strong mutual coupling between the receive coils deeming it unfit for the portable detector; however, the findings of the work presented and the selection criterion developed has aided the future design of a suitable coil array. Expected signal levels from minimum metal mine detection were calculated and helped aide in the design of future detectors to ensure suitable SNR performance is achieved. A portable detector has been developed using the sensor head presented within this thesis. Work still lies ahead to achieve the complete detector capable of performing target characterisation and clutter elimination; however, significant advances have been made and are presented throughout this thesis.

The far-infrared and millimeter wave (FIR/mmW) (wavelength 75 micrometer to 10 mm) portion of the electromagnetic spectrum is fairly underdeveloped technologically, owing to the large amount of atmospheric attenuation in that range. At present, the FIR/mmW region is lacking in compact, high-brightness radiation sources and practical imaging systems. This dissertation focuses on development of two complementary technologies in this area - an active mmW imaging system and high-reflectivity Bragg mirrors for the FIR p-Ge laser. The imaging system uses a vector network analyzer in the frequency range of 90-140 GHz as the radiation source and receiver. Raster scanning is used to map a two-dimensional field of view, demonstrating the detection and imaging of buried plastic landmines. Principal components analysis is used for hyperspectral signal processing, where a series of images is taken at discrete frequencies. Results are obtained as a function of depth and disturbance of the soil surface. In support of this study, various types of soils were characterized for scattering loss across the mmW/FIR region, with measured results compared to theory. This mmW imaging system was also used to demonstrate imaging through walls and other obscuring materials, as well as for imaging of rocks beneath volcanic sand, simulating the conditions encountered by an imaging system on a Mars rover vehicle. Furthermore, a high-reflectivity Si-etalon FIR mirror design was developed and demonstrated as a cavity mirror for the p-Ge laser. These components stand to have a number of systems-level impacts on FIR imagers. In the context of an active illuminator, they may allow narrowband selection from the broad emission spectrum of the p-Ge laser source. These mirrors can also be used in a Fabry-Perot FIR scanning spectrometer, where the resulting high finesse would give discrimination advantages in chemical sensing and astrophysical spectroscopy applications.