Landsat Thematic Mapper Imagery of San Francisco
These scenes shows Landsat Thematic Mapper data of the city of San Francisco and of the San Francisco Bay Area. The first image, which is predominately brown in color, is a "natural color" image which uses the Thematic Mapper bands 3, 2, and 1 displayed as red, green, and blue respectively. This yields a color scheme approximately the same as those seen by the human eye. The other two scenes use data from the infrared portions of the electromagnetic spectrum to maximize the range of wavelengths shown. These images use the shortwave infrared (TM band 5), infrared (TM band 4), and visible green (TM band 2) channels. Digital elevation data was used in the two city scenes to create three dimensional terrain, which is vertically exaggerated by a factor of three to show the relief of the land.
The Golden Gate bridge is visible at the top of the San Francisco city image, as well as the San Bruno mountains south of the city in the foreground of both city images. The strong brown/grey tone of the natural colour image is a result of the data being taken during the early autumn when ground cover is very dry and the land tends to appear somewhat barren. In the TM 542 scenes, barren exposed land appears red to pink, vegetation appears green, water is dark blue, and the light blue along the coastal shore is surf.