Fundamentals of Spatial Data

Gerrit Günther

July. 2022

Geographic Data Models

© http://eo4geo.sbg.ac.at/GEOF/Basic-GIS-knowledge-and-raster-data/rastervector.png

© http://eo4geo.sbg.ac.at/GEOF/Basic-GIS-knowledge-and-raster-data/rastervector.png






Vector Data

Vector Data - Discrete Entities

Vector Data - Discrete Entities

Vector Data - Discrete Entities

Vector Data - Well Known Text (WKT)

Coordinate Precision






Raster Data

Raster Data - A Matrix for Continiuos Data

Raster Data - A Matrix for Continiuos Data

Comparison of Geographic Data Models

© http://eo4geo.sbg.ac.at/GEOF/Basic-GIS-knowledge-and-raster-data/rastervector.png

© http://eo4geo.sbg.ac.at/GEOF/Basic-GIS-knowledge-and-raster-data/rastervector.png






If a cell can only hold a single value… how we assign the values?






It depends…

Different Ways of Rasterization

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png

Different Ways of Rasterization

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png

Different Ways of Rasterization

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png

© https://geocompr.robinlovelace.net/06-raster-vector_files/figure-html/vector-rasterization2-1.png






Any questions so far?






Common Vector Data Formats

Vector Data - CSV

Vector Data - Shapefile

… avoid if you can ;)

Vector Data - GeoPackage

Vector Data in R






Common Raster Data Formats

Raster Data - GeoTiff

Raster Data - Additional Formats

Use .tif ;)

Raster Data in R






Questions?






Time to look at some code :)

Recommendations

Geocomputation with R (https://geocompr.robinlovelace.net/)

sf: https://r-spatial.github.io/sf/

terra: https://rspatial.org/terra/