In physics, the spectral density, or more correctly the power spectral density of a given bandwidth of electromagnetic radiation is the total power in this bandwidth divided by the specified bandwidth.
Spectral density is usually expressed in watts per hertz (W/Hz).
All Wikipedia text
is available under the
terms of the GNU Free Documentation License
Search Encyclopedia
Search over one million articles, find something about almost anything!
... in promoting the take-up of digital television.
BBC News 24 broadcasts from the BBC News Centre in BBC Television Centre, West London.
See also: List of British ...