Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Drone-borne hyperspectral remote sensing of REE deposits in Namibia
Booysen, R.; Gloaguen, R.; Zimmermann, R.ORC; Jakob, S.
Traditional exploration techniques are mainly based on extensive field work supported by geophysical surveying. These techniques can be restricted by field accessibility, financial status, area size and climate. Therefore, we suggest to increase the use of multi-scale hyperspectral remote sensing in order to decrease conventional restrictions in the exploration of minerals through the use of Unmanned Aerial Systems (UAS). We further argue that the addition of drone based hyperspectral data can vastly improve the accuracy of field mapping in future mineral exploration. Drone-borne measurements can supplement and direct geological observation immediately in the field and therefore allow better integration with in-situ ground investigations. In particular, in inaccessible and remote areas with little infra-structure, such systems are beneficial because it allows a systematic, dense and completely non-invasive surveying, which is often not possible using ground- based techniques. We use a hyperspectral camera attached to a hexacopter to acquire data from the visible (VIS) to the near-infrared (NIR) range of the electromagnetic spectrum. The hyperspectral data is then corrected of radiometric and geometric distortions using a new python-based in-house toolbox. In addition, high-resolution Digital Surface Models (DSM) and Orthomosaics are generated from drone data using Structure- from-Motion photogrammetry. The corrected data provide information on the spectral signatures of outcropping lithologies to the field geologists and the exploration teams. This is achieved by using end-member modelling and classification techniques such as non- linear machine learning algorithms, e.g., Neural Networks and tree based methods. The validation of the hyperspectral data is performed via field spectroscopy and portable XRF. The proposed method is currently tested on carbonatite-hosted REE occurrences in several locations in Namibia. These locations are characterised by difficult terrains and remote environments, that would impede or restrict traditional field surveys. Preliminary results indicate that UAS-based surveying has a very high potential in fundamentally lowering the acquisition costs and increasing the information potential of data captured in the field.
  • Lecture (Conference)
    10th EARSeL SIG Imaging Spectroscopy Workshop, 19.-21.04.2017, Zürich, Schweiz

Publ.-Id: 24907 - Permalink