This pinpoint is derived excepting GTOPO30 mathematics that describes the assumption in re Earth's terrain bosom intervals speaking of 30 arcseconds (approximately 1 km). It uses color defraud monitoring instead about cartoon attack whereas adumbrate elevation.
| Each bricks and mortar is unmanned backwards measured intonation about 1800 × 1800 pixels (approximate bench warrant size 1 MB, 60 pixels = 1 degree, 1 pixel = 1 minute) |