Integrating Orbital and Proximal Thermal Infrared Remote Sensing Data for Mapping Ilmenite in the Coastal Plain of Rio Grande do Sul, Brazil

Hallal, G.P.; Espinoza, J.M.A..; Veettil, B.K.; Albuquerque, M.G.; Porcher, C.; Da Silva, M.R., and Rolim, S.B.A., 2024. Integrating orbital and proximal thermal infrared remote sensing data for mapping ilmenite in the coastal plain of Rio Grande do Sul, Brazil. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M.(eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar).Journal of Coastal Research, Special Issue No. 113, pp. 783-787. Charlotte (North Carolina), ISSN 0749-0208. Titanium oxide is of fundamental importance for the economy of countries as it is a raw material for many industries. The main source of this oxide is the mineral ilmenite, found mainly in coastal sedimentary deposits. Thermal infrared (TIR) remote sensing is useful for prospecting oxide minerals through molecular vibration bands above 8 µm. We measured the spectral signature of ilmenite in the laboratory with µFT-IR between 8 and 14 µm and identified an absorption feature. This signature was used as input data in the Spectral Angle Mapper (SAM) classification algorithm. The SAM was applied in the land surface emissivity (LSE) product of the Advanced Spaceborne Thermal Emission Radiometer (ASTER) sensor from two locations on the southern coast of Brazil. Our results show that it is possible to map ilmenite through the integration of orbital and proximal TIR data, non-destructively, quickly, and at a low cost.