Eastern Himalayas, satellite image. North is at top. Cloud cover is white. The snow-capped peaks are light blue, the lower slopes are covered in vegetation (green). Areas of barren earth (including the valley bottom) are red. A large lake is at top right (dark blue). This image has been achieved using thematic mapper (TM) instrumentation. The TM sensor collects radiometric data in seven spectral bands. Each band gathers particular information on different surface features. The bands are combined to achieve a particular image. This image was achieved using Bands: 2, for estimation of vegetation vigour, 4, for determination of biomass content and 7, for discrimination of rock types. These bands have a spectral range of 0.52 to 2.35 micrometres.