This chapter focuses on the practical aspects of map production, emphasizing data acquisition from open-access platforms and visualization using modern geospatial tools. The platforms discussed include Copernicus Open Access Hub, NASA’s Earthdata services, QGIS, Google Earth Pro, and QField. This hands-on approach will equip users with the skills to retrieve, process, and analyze geospatial data effectively.
The Copernicus Open Access Hub provides free and open access to
Sentinel satellite data, including Sentinel-1 (SAR), Sentinel-2 (optical
multispectral imagery), and Sentinel-3 (ocean and land monitoring).
Sentinel-2, in particular, is ideal for land-use mapping due to its
high-resolution (10 m) multispectral bands.
Data Retrieval:
Visit the Copernicus Open Access Hub.
Use the EO Browser (EO Browser) for a user-friendly interface, eliminating the need for account creation.
Search by area of interest and select time ranges for desired images.
Download imagery in GeoTIFF or JPEG2000 formats, typically processed at Level-1C or Level-2A (surface reflectance).
NASA offers diverse platforms such as Earthdata Search, Worldview, and GIBS for accessing remote sensing data from sensors like MODIS, VIIRS, and Landsat. These datasets are essential for large-scale environmental monitoring.
Data Retrieval:
For visualizations, use NASA Worldview to browse and overlay live data layers. Export data in PNG or KMZ formats.
For more detailed data, visit Earthdata Search, where you can directly download georeferenced imagery and geophysical parameters in NetCDF or HDF formats.
GIBS supports API-based access to imagery, offering JPEG or PNG for seamless integration with mapping tools.
QGIS is a free and open-source GIS software that supports data visualization, analysis, and map production. It accommodates raster and vector data formats and offers an array of plugins for remote sensing and geospatial tasks. The plugins range from importing Keyhole Markup Language (KML) .kml files to automatically downloading Shuttle Radar Topography Mission (SRTM) digital elevation model files for specified locations and even more.
As an external great source, walkthrough textual and screenshot tutorials of here are great, especially the basic and intermediate operations are definitely must-see.
Core Functionalities:
Import raster datasets (e.g., GeoTIFF) and overlay vector data (e.g., shapefiles, GeoJSON).
Style data layers using symbology and color ramps for visualization.
Integrate live basemaps using XYZ tiles from providers like OpenStreetMap or Google Satellite.
Google Earth Pro is a desktop application for exploring and visualizing high-resolution 3D maps. It is particularly effective for understanding terrain features and creating temporal analyses. Looking at past high-resolution images from aircrafts starting from 2010s, measuring the length of routes, extracting elevation profiles, flight simulation, and generally having an easy-to-use general user interface (GUI) are among its very positive features.
Data Retrieval:
Use the search tool to zoom into regions of interest and explore historical imagery for temporal analysis.
Export images as JPEGs or PDFs for use in presentations or reports.
Import/Create GIS data such as KML/KMZ files for overlaying study areas.
Create a path, measure its length and elevation profile and make modifications
QField is a mobile application designed to integrate with QGIS, facilitating real-time data collection and synchronization.
Core Functionalities:
Export QGIS projects to QField and use mobile devices to collect field data.
Gather geolocated points, lines, or polygons with attribute information in offline or online modes.
Sync data back to QGIS for post-fieldwork analysis.
