Comparison: Satellite Imagery (1)

We like to give credit where it’s due, and in this case it goes to NGI.

The aerial photography provided by the Chief Directorate: National Geospatial Information (CD:NGI) is probably one of the most underrated sets of geospatial data in South Africa. This free imagery is not only essential for use as spatial reference in GIS and CAD software, but can be used in quantitative image analyses such as digital elevation model (DEM) extraction, and flood hazard mapping, as well as land cover classification and radio frequency clutter maps (now a work in progress for our team). Needless to say, these and many other sets of derived products have huge societal benefits.

Get access to this data at http://www.cdngiportal.co.za/CDNGIPortal/.

Also see how we have utilised these products to bring you DEM extraction and flood hazard mapping.

The featured image compares NGI 25cm imagery from 2018 (left), with NGI 50cm imagery from 2015 (middle), and Google satellite imagery (right).