All >
Science >
Weather - This type of satellite imagery uses reflected sunlight (this is actually reflected solar radiation) to see things in the atmosphere and on the Earth's surface. Clouds and fresh snow are excellent reflectors, so they appear white on the imagery. Clouds can be distinguished from snow, because clouds move and snow does not move. Meanwhile, the ground reflects less sunlight, so it appears black on the imagery. The satellite uses its 0.55 to 0.75 micrometer (um) channel to detect this reflected sunlight. Since this imagery relies on reflected imagery, it cannot be used during night.
NOAA National Weather Service - Cite This Source - This Definition - Browse Related Terms: Infrared Satellite Imagery, IR, Non-Uniform Visibility, SAT, VIS, VSB, VSBY
All >
Medicine >
Cancer - (VIH-zhoo-ul A-nuh-log skayl) A tool used to help a person rate the intensity of certain sensations and feelings, such as pain. The visual analog scale for pain is a straight line with one end meaning no pain and the other end meaning the worst pain imaginable. A patient marks a point on the line that matches the amount of pain he or she feels. It may be used to help choose the right dose of pain medicine. Also called VAS.
National Cancer Institute - Cite This Source - This Definition - Browse Related Terms: Atypical, Constipation, hot flash, Hot flashes, palliation, palpitation, phantom limb pain, psychological, self-esteem, VAS, Zheng (jung)
All >
Technology >
Telecommunications - A means for delivering video frames from one point to another; a sequence of frames submitted to the channel input results in a similar (not necessarily identical) sequence of frames at the channel output. Note: The visual channel may be comprised of the following components: video format conversion devices, encoders (compressors) and decoders (decompressors), rate smoothing buffers, multiplexors and demultiplexors, modulators and demodulators, transmission facilities, switches, multi-point conference units, and other components necessary to achieve the desired channel characteristics. [After T1.801.04-1997]
ATIS - Cite This Source - This Definition - Browse Related Terms: audio channel, data channel
All >
Science >
Weather - The portion of the electromagnetic spectrum to which the eye is sensitive, i.e., light with wavelengths between 0.4 and 0.7 micrometers. Compare shortwave radiation and longwave radiation.
NOAA National Weather Service - Cite This Source - This Definition - Browse Related Terms: blackbody, Blackbody Radiation, dispersion, gamma ray, Graybody, Longwave Radiation, Microwave, Photosphere, radiation, Radiation Laws, Shortwave radiation, ultraviolet radiation, X-Rays
m to 0.7