Knowledge / Mining & Geoscience / GIS, Data & Remote Sensing

GIS, Data & Remote Sensing

GIS, Data and Remote Sensing: Datums, ellipsoids and projections — and how a site moves hundreds of metres when the datum is wrong; Points, lines, polygons and grids; resolution and support; and which questions each model can answer; DSM versus DTM, SRTM, Copernicus and.

All 8 articles are published. Each one states what it needs, what can be concluded with it, and what cannot — and every one stays marked DRAFT until it has had independent geological review.

1. Coordinate reference systems publishedDatums, ellipsoids and projections — and how a site moves hundreds of metres when the datum is wrong.
2. Vector and raster data publishedPoints, lines, polygons and grids; resolution and support; and which questions each model can answer.
3. Digital elevation models publishedDSM versus DTM, SRTM, Copernicus and lidar, vertical accuracy, and the terrain derivatives geologists use.
4. Multispectral remote sensing publishedLandsat, Sentinel-2 and ASTER bands, band ratios for alteration minerals, and what vegetation and cover hide.
5. Hyperspectral remote sensing publishedAbsorption features, spectral libraries and unmixing — what EMIT, EnMAP and airborne sensors can identify.
6. Radar and InSAR publishedSAR backscatter, interferometry and ground deformation — monitoring subsidence and dam movement from orbit.
7. Gridding geophysical and geochemical data publishedLine and point data to grids, cell size, interpolation artefacts, and why a pretty map can invent an anomaly.
8. Spatial data provenance and licensing publishedWho made a dataset, under what licence, at what scale — and why an unlicensed layer is a liability, not an asset.