South Africa 50cm Colour Imagery

<div style='text-align: left;'><div><div><p><span><span>In 2005, National Geo-spatial Information noticed a global trend towards digital image acquisition and decided to invest in a digital camera (an Intergraph DMC). Since 2008, all images have been captured digitally with this camera.</span></span><span><span><span><span>This meant that the acquisition of the traditional photo-scale had now been replaced with a Ground Sample Distance (GSD). The ground sample distance is the size of 1 pixel on the ground and is influenced by the flying height and focal length.</span></span></span></span></p><p><span>Currently, 12-bit images are captured in RGB (true colour), Near infra-red and Panchromatic, with a GSD of 0.5m They are stored as Tiff files with a JPEG compression of Q=3; with tiles and a full set of overviews. Each DMC image is approximately 7km by 3.8km and they are mosaiced together to fit the 1:10 000 reference sheets after orthorectification. The aim is to capture 40% of the country every 3 years and the remaining areas every 5 years.</span><span></span></p><p><span></span></p><p><span>The current dataset displays imagery captured between 2008 and 2012 and should only be used for reference purposes.</span></p><p><span></span></p></div></div></div>