ABSTRACT
Physical studies of the mountain environment deal with a great variety of natural and man-induced problems. This chapter outlines some characteristics of the more common remote-sensing systems that pertain to various types of mountain problems. Operational remote sensing is generally restricted to the visible, photographic infrared, thermal infrared, and microwave and radar portions of the electromagnetic spectrum. Remote-sensing at shorter and longer wavelengths is seriously hampered by a number of factors, most notably atmospheric absorption, low natural emissions, and man-made and natural noise. Remote-sensing systems used in the visible and photographic infrared bands are all passive; the sun is the external source of electromagnetic radiation. Remote-sensing data from the visible spectrum is probably the easiest to interpret, since our eyes are also tuned to visible light. A variety of remote-sensing data is available to aid the monitoring and mapping of the mountain environment.
