Landmine Detection and Discrimination using High-Pressure Waterjets

Methods of locating and identifying buried landmines using high-pressure waterjets were investigated. Methods were based on the sound produced when the waterjet strikes a buried object. Three classification techniques were studied, based on temporal, spectral, and a combination of temporal and spectral approaches using weighted density distribution functions, a maximum likelihood approach, and hidden Markov models, respectively. Methods were tested with laboratory data from low-metal content simulants and with field data from inert real landmines. Results show that the sound made when the waterjet hit a buried object could be classified with a 90% detection rate and an 18% false alarm rate. In a blind field test using 3 types of harmless objects and 7 types of landmines, buried objects could be accurately classified as harmful or harmless 60%-90% of the time. High-pressure waterjets may serve as a useful companion to conventional detection and classification methods

Analysing the influence of TNT on Southern African trees grass and shrubs using in-situ hyperspectral data

Landmines pose a significant risk to the health and livelihood of millions of people in war-torn countries. From a humanitarian point of view, these hidden dangers must be detected and removed. Several detection methods exist, including ground-penetrating radar, sniffer dogs and rats. It is a tedious process and can take months to clear only a single minefield. This study investigates whether TNT from leaking landmines can be detected using hyperspectral remote sensing of plant foliage, with the aim of being an area reduction aid. Increasing concentrations of TNT was administered to a study sample of five species of trees, five species of grasses and four species of shrubs, and leaf-clip readings were taken at regular intervals with a field spectrometer. Statistical correlation testing of seven plant health indices (red-edge position, first derivative reflectance, normalised difference water index, moisture stress index, water band index, photochemical reflectance index and nitrogen index) was done on the results of the readings. TNT has a mixed effect on the health of the tested plants, with some species displaying adverse effects of TNT on their health, while others proved to be healthier or more resilient against the effects. Results also varied in magnitude. Even in a single species, differing concentrations TNT lead to varying results. The various indices delivered varying results, with some indices delivering inconclusive results. Positive results were yielded from the REP analysis, indicating this as a possible index to use in landmine detection.Dissertation (MSc)--University of Pretoria, 2017.Geography, Geoinformatics and MeteorologyMScUnrestricte