Landsat

A photo of the central and eastern Mediterranean region, taken by an orbiting satellite. The first vehicle in the Landsat series took over 300,000 pictures of the Earth's surface between 1972 and 1978; subsequent Landsats have contributed greatly to accurate mapping of the world's remoter regions.

Landsat 4, launched on 16 July 1982, orbited the Earth 14 times a day (with repeat coverage of the Equator once every 16 days) until an on-board data transmitter failed in August 1993. The satellite carried the thematic mapper (TM), which detected reflected radiation from the Earth's surface in the visible and infrared wavelengths.

Series of US satellites launched from 1972 that monitor the Earth's resources and the effects of pollution, deforestation, and desertification. The latest in the series, Landsat 7, was launched on 15 April 1999.

Landsat 1, originally called ERTS-A (Earth Resources Technology Satellite-A), orbited 1972–75, acquiring more than 300,000 images of the Earth's surface. Landsat 4, launched in June 1982, contained a new kind of technology, the thematic mapper (TM). The National Oceanic and Atmospheric Administration took over the running of the Landsat programme from NASA in 1983.