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Roger Bivand: Coordinate Reference Systems
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Talk by Roger Bivand, Professor Emeritus, Norwegian School of Economics, at the University of Chicago's Center for Spatial Data Science (Jan. 19, 2023).
The FOSS ecosystem is very dependent on the PROJ library, which has changed a great deal since PROJ.4. PROJ 5 introduced transformation pipelines, PROJ 6 an SQLite database of CRS, transformations, etc., and upgraded CRS representation from the legacy PROJ.4 string to WKT2-2019. PROJ 7 introduced a content download network for accessing transformation grids. We are now at PROJ 9.1.1. GDAL 3 requires PROJ 6 or greater, and is now tightly integrated with PROJ. In addition, modern vector file formats such as GeoPackage assume a basic geographical CRS where none is given, so we need to innovate to express a missing planar CRS.
The FOSS ecosystem is very dependent on the PROJ library, which has changed a great deal since PROJ.4. PROJ 5 introduced transformation pipelines, PROJ 6 an SQLite database of CRS, transformations, etc., and upgraded CRS representation from the legacy PROJ.4 string to WKT2-2019. PROJ 7 introduced a content download network for accessing transformation grids. We are now at PROJ 9.1.1. GDAL 3 requires PROJ 6 or greater, and is now tightly integrated with PROJ. In addition, modern vector file formats such as GeoPackage assume a basic geographical CRS where none is given, so we need to innovate to express a missing planar CRS.