Evaluating multi-resolution remote sensing data - A knowledge-driven approach to geological remote sensing in a high-sulphidation epithermal system

This PhD research develops and tests a resolution-first, knowledge-based framework for characterising a high-sulphidation epithermal system using geological remote sensing. The study focuses on a single lithocap environment and uses laboratory, airborne and spaceborne datasets spanning the VNIR, SWIR, and LWIR wavelength ranges. The aim is to determine (i) what information each spatial and spectral resolution can independently provide about a mineral system and (ii) the possible multiplier effect obtained when combining resolutions. The work targets four classes of geological products that can be derived from a remote or proximal sensing source: hydrothermal alteration mineralogy, rock-forming mineralogy, fluid composition, and fluid emplacement.Methodologically, the thesis applies a consistent, physics-based image analysis workflow across all resolutions. Laboratory hyperspectral measurements in the SWIR and LWIR ranges are first used to define and validate mineral spectra, textural relationships, wavelength shifts and kaolin-group subtypes. These spectra provide the basis for interpreting imaging datasets and serve as the reference for validation. Airborne hyperspectral SWIR and LWIR data are then processed to deposit scale using imaging processing techniques, such as band ratios, spectral indices, and absorption feature/emissivity minima mapping. The same indices and ratios are applied to spaceborne hyperspectral SWIR and multispectral VNIR-SWIR-TIR data to generate directly comparable products, ranging from regional to deposit scales. All interpretations are made using a knowledge-based approach, anchored in mineral spectroscopy and epithermal system models, rather than data-driven classification alone.The study uses only geological and remotely sensed data; no personal data are involved. Laboratory measurements were conducted on rock and mineral samples under standard procedures. Airborne and spaceborne datasets were obtained from public and commercial providers under their licence conditions and applicable national regulations for airborne surveys. As such, no specific ethical review was required, and all data collection adhered to legal and regulatory requirements. The combination of clearly documented processing steps, physics-based indices, and cross-scale validation is designed to make the workflow transparent and reproducible, enabling its application to other mineral systems and survey designs.