Among all the forensic applications in which it has become an important exploration tool, ground penetrating radar (GPR) methodology is being increasingly adopted for buried landmine localisation, a framework in which it is expected to improve the operations efficiency, given the high resolution imaging capability and the possibility of detecting both metallic and non-metallic landmines. In this context, this study presents landmine detection equipment based on multi-polarisation: a ground coupled GPR platform, which ensures suitable penetration/resolution performance without affecting the safety of surveys, thanks to the inclusion of a flexible ballistic shielding for supporting eventual blasts. The experimental results have shown that not only can the blanket absorb blast-induced flying fragments impacts, but that it also allows for the acquisition of data with the accuracy required to generate a correct 3D reconstruction of the subsurface. The produced GPR volume is then processed through an automated learning scheme based on a Convolutional Neural Network (CNN) capable of detecting buried objects with a high degree of accuracy.

https://www.mdpi.com/2072-4292/12/4/717/pdf

Ballistic Ground Penetrating Radar Equipment for Blast-Exposed Security Applications

Some of the recent advances in ground penetrating radar (GPR) technology are discussed in this paper; in particular the move to, and potential value addition offered by, the 3D approach to surveying over the more conventional 2D approach. Case studies at two platinum mines in the Bushveld Complex are used to stress the fact that the niche role for GPR is that of immediate hangingwall assessment, aimed at identifying geological features that could potentially result in falls of ground (FOGs). The paper also highlights the obstacles that still need to be overcome to enable GPR to become a routine tool in local mining operations, and recommendations are offered on how to address these obstacles through ongoing research efforts.

/pdf/the-use-of-3d-ground-penetrating-radar-to-mitigate-the-risk-2l36sw0mfj.pdf

The use of 3D ground penetrating radar to mitigate the risk associated with falls of ground in Bushveld Complex platinum mines

Understanding the process of decomposition is extremely important and aids in criminal investigations, especially when attempting to estimate the post mortem interval (PMI). Although several studies have been conducted on the decomposition patterns in surface remains, much less is known about this process in buried remains. By quantifying decomposition rates, factors influencing decomposition and research on the process of decomposition can be standardised and validated in a South African setting. The aim of this study was to record decomposition stages and rates of buried remains and to compare it to that of remains decomposing on the surface. Twenty five pigs (Sus scrofa; 4580 kg) were buried and excavated at different post mortem intervals [7 days (1 week), 14 days (2 weeks), 33 days (1 month), 92 days (3 months) and 183 days (6 months)]. Stages of decomposition were scored according to separate categories for different anatomical regions based on standardised methods, and photographed. The point values for each region were added to determine the total body score (TBS), which represents the stage of decomposition for each pig. When studying decomposition, accumulated degree days (ADD) are effective in standardising the effect of variables (i.e., temperature) that influence the decay process. It also enables researchers to replicate experiments and compare results. In this study, ADD were used to measure the rate of decomposition and to compare decomposition rates between buried and surface remains. Results indicated that early stages of decomposition occured rapidly for both surface and buried remains within 7-33 days. Differences in the degree of decay were especially noticeable with the buried, 7 day interval pigs that displayed variations in discolouration in the lower abdomen and trunk. Between 14 and 33 days, buried pigs displayed common features associated with the early stages of decomposition, such as discolouration and bloating. The pigs then reached a stage of advanced decay where little change was observed in the next ±90-183 days after internment. Similar patterns of decomposition were observed for surface remains with rapid decay during the early stages of decay where after a plateau phase was reached during advanced decay. However, as expected, the surface remains reached higher TBS scores during similar intervals. iii In this study, the decomposition rates of buried remains were mostly influenced by being buried at an average depth of 0.75 m which could have resulted in lower in-soil temperatures and limited insect activity at a depth of 0.75 m on the remains. Also, adipocere presented itself on the remains with the 33 day PMI pigs, the 92 day PMI pigs and 183 day PMI pigs. Adipocere is capable of degrading over a prolonged period which reduces the rate of decay in a conducive environment (i.e., burial in soil). Overall, surface and buried pigs decompose with similar patterns, but buried pigs decompose at a much slower rate, reaching lower TBS values relative to similar PMIs in surface remains. This suggests that burial does have a significant effect on the rate of decomposition. Results from this study suggest that when using TBS guidelines on buried remains in the Central Highveld region of South Africa, buried remains will have, on average, a lower TBS score (7.4) than surface remains within a similar post mortem interval.

Decomposition patterns of buried remains in the Central Highveld region of South Africa

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.3302

Unveiling buried aeolian landscapes: reconstructing a late Holocene dune environment using 3D ground-penetrating radar

A controlled three-dimensional ground penetrating radar monitoring study over simulated clandestine
graves was conducted near Pretoria, South Africa, in which the detectability of graves as a
function of post-burial interval was assessed, as this is of particular interest to local forensic investigators.
It was demonstrated that the site-specific environmental parameter (a clay-rich loamy soil
with poor drainage) and heavy seasonal rainfall (as confirmed by ground-penetrating-radar-derived
soil moisture estimates) drastically compromised the long-term grave detectability, especially when
adopting a three-dimensional depth slice analysis approach. It is also seen that the disturbed burial
zone is the major contributor to the total grave anomaly rather than the buried body due to the combination
of environmental parameters and the absence of buried artefacts. This paper also advocates
the combined use of different data representations (two-dimensional and three-dimensional) to
increase the likelihood of detecting subtle grave anomalies.

/pdf/a-controlled-monitoring-study-of-simulated-clandestine-1hxu8hl507.pdf

Michael van Schoor

Papers

A controlled monitoring study of simulated clandestine graves using 3D ground penetrating radar