1. Introduction into GIS, Open Geospatial Datasets

A brief introduction to Geographical Information Systems (GIS) and a quick overview of various open geospatial datasets.

GIS is a type of database containing geographic data, combined with software tools for managing, analyzing, and visualizing those data (source: Wikipedia)
Geospatial data describe phenomena for which location is relevant

Examples of geospatial data:

administrative boundaries
rivers, lakes
roads
elevation model
contours
...

Access policies:

open data
- can be freely used, re-used and redistributed by anyone (source: Open Definition)
- Example of licenses: Creative Commons (CC BY 4.0, CC0), Open Data Commons (ODbL), etc.
proprietary data
- owned by an individual or organization, protected by copyright

Open Geospatial Data - Overview

Example of global datasets:

Natural Earth Data - cultural, physical data
USGS Earth Explorer - Earth Observation (EO) data, land cover, digital elevation models
OpenStreetMap - high spatial resolution cultural vector data
Esri Open Data Hub - various data
NASA Socioeconomic Data and Applications Center - agriculture, climate and health data
Open Topography - LiDAR
UNEP Environmental Data Explorer - population, forests, emissions, disasters, etc.
NASA Earth Observations - atmosphere, energy, land, life, ocean
Sentinel Satellite Data - EO data
Terra Populus - land cover, land use, and climate
...

Situation in Europe overview

How to search for open data in Europe

EU-based catalogue https://data.europa.eu/en

Example: NUTS1 data (keyword: NUTS1 administrative units publisher: Eurostat)

National catalogues:

First experience with the data

What software use to open geospatial data

GIS desktop applications:

Esri ArcGIS https://arcgis.com
QGIS https://qgis.org (open source)
GRASS GIS https://grass.osgeo.org (open source)
...

Quick info on QGIS:

Open source (GNU General Public License)
A lot of plugins
- Available at https://plugins.qgis.org/

Data manipulations

Data queries in QGIS:

Attribute-based (QGIS documentation)
Spatial (QGIS documentation)

Workflow example in QGIS:

Dissolve NUTS region by country code Vector > Geoprocessing Tools > Dissolve
Query NUTS layer by country code Select by Expression
Query NUTS layer by spatial relationship Vector > Research Tools > Select by Location

Workflow example in Esri ArcGIS Pro:

Data examples

OpenStreetMap

General info:

https://www.openstreetmap.org
Vector
Community-based
Global scale
Founded in 2004 in the UK
Getting global in 2006
- OpenStreetMap foundation founded
Data primitives
- Nodes
- Ways
- Relations
Pros
- Community-based
- Open
- More than 100 GBs
- Global scale
- Very detailed information
- Community is independent to the project
Cons
- Community-based
- Non-homogenous cover
- No quality consistence
Open for contribution - iD Editor
- https://www.openstreetmap.org/login?referer=%2Fedit%3Feditor%3Did
- Documentation: https://learnosm.org/en/beginner/id-editor/

Associated projects:

HOTOSM
- https://www.hotosm.org/
- Humanitarian action and community development through open mapping
mapy.cz
- https://mapy.cz/
- OSM serve as base data for foreign countries

Data download:

Simple export
- https://www.openstreetmap.org/export
Overpass turbo
- https://overpass-turbo.eu/
- Runs Overpass API queries
QGIS plugin - OSMDownloader
- https://plugins.qgis.org/plugins/OSMDownloader/

Digital Elevation Model

International programmes:

EU-DEM
- Available through https://data.europa.eu/en (keyword: eu-dem)
- Raster
- EEA members and cooperating countries
SRTM
- Available at https://srtm.csi.cgiar.org/srtmdata/
- Shuttle radar topography mission
- Near-global scale
- Measured using SAR

Simple processing examples in QGIS:

Compute slope
- Raster > Analysis > Slope
Compute aspect
- Raster > Analysis > Aspect
Compute hillshade
- Raster > Analysis > Hillshade

Earth Observation data

General info:

Data about the physical, chemical, and biological systems
Natural as well as manmade environment
Grid-structured data with spatial, additionaly also temporal information
Sources
- Remote sensing
- Measurements
Examples
- Photos
- Radar images
- Sonar images
- Measurements
Included information
- Spectral information from satellites
- Thermometer measurements
- Altimeter measurements
- Wind gauge measurements
- Buoy measurements

Examples of raster satellite data sources:

Open data
- Global
  - Sentinel
    - https://sentinel.esa.int/web/sentinel/missions
    - Sentinel-1: Land and ocean monitoring with radar imaging
    - Sentinel-2: Land monitoring
    - Sentinel-3: Marine observation
    - Sentinel-4: Air quality monitoring (to be launched in 2024)
    - Sentinel-5: Air quality monitoring
    - Sentinel-5P: Sentinel-5 precursor
    - Sentinel-6: Sea-surface altimetry
  - Landsat
    - https://earth.esa.int/eogateway/missions/landsat
    - Landsat-1 to 5: Resolution of 60 to 80 m
    - Landsat-1: 1972 -- 1978
    - Landsat-2: 1975 -- 1982
    - Landsat-3: 1978 -- 1983
    - Landsat-4: 1982 -- 1993
    - Landsat-5: 1984 -- 1999 (limited work acquisitions until 2013)
    - Landsat-7: 1999
      - Still operational
      - Land and coastal areas, shallow waters
      - 8 bands
      - Resolution of 15 to 60 m
    - Landsat-8: 2013
      - Still operational
      - Land and coastal areas, shallow waters
      - 11 bands (9 spectral bands, 2 thermal bands)
      - Spectral bands resolution 15 to 30 m, thermal bands 100 m
- Areas of interest
  - VENµS
    - Data and areas of interest available at https://www.theia-land.fr/en/product/venus/
    - Resolution of 5 to 10 m
Proprietary data
- Pleiades
  - https://earth.esa.int/eogateway/missions/pleiades
  - Owned by Airbus
  - 5 bands
  - Resolution of 0.5 to 2 m
  - Data availability: 2011 onwards
- SPOT 6/7
  - https://earth.esa.int/eogateway/missions/spot
  - Owned by Airbus
  - 5 bands
  - Resolution of 1.5 to 6 m
  - Data availability: 2012 onwards
- WorldView
  - https://earth.esa.int/eogateway/missions/worldview
  - Owned by Maxar
  - 5 bands
  - Resolution of 0.3 to 2 m
  - Data availability: 2009 onwards

Sentinel-2 data:

Global coverage
13 bands
Spatial resolution of 10 to 60 m
Data availability: 2015 onwards
Revisit time of 2 days
Land and coastal areas, shallow waters
Download examples
- Web-based
  - Sentinel Hub: https://apps.sentinel-hub.com/eo-browser/
  - Google Earth Engine: https://earthengine.google.com/
- GIS software plugins
  - QGIS SentinelHub plugin
    - https://plugins.qgis.org/plugins/SentinelHub/
    - Uses Sentinel Hub services in background
  - QGIS Sentinel-2 Download plugin
    - https://plugins.qgis.org/plugins/sentinel2_download/
    - Uses Google Earth Engine in background