These scenes show Pittsburgh and the countryside around it as seen by the Landsat Thematic Mapper (TM) instrument. Pittsburgh is built around the confluence of the Monongahela and Allegheny Rivers which join in the city to form the Ohio River. The terrain of the area is also shown exaggerated by a factor of three to emphasis terrain features such as the Appalachian Mountains and the river valleys. In the countryside image, north is up, the Monongahela River runs in from the south into the city while the Allegheny comes in from the north and the Ohio runs westward (to the left) out to the scene's edge. The image of the city appears from the perspective of a viewer above the Allegheny River looking southwards towards the city.
The shortwave infrared (TM band 5), infrared (TM band 4), and visible green (TM band 2) channels are displayed in the images as red, green, and blue respectively. In this combination, barren and/or recently cultivated land appears red to pink, vegetation appears green, water is dark blue, and artificial structures of concrete and asphalt appear dark gray or black.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0