riometern.
/riːˈɒmᵻtə/, U.S. /riˈɑməd(ə)r/ Atmospheric Physics.
An instrument for measuring the absorption of cosmic radio waves by the ionosphere.The riometer operates by comparing the measured radio noise with a long-term average value; the difference corresponds to the amount of ionospheric absorption.
ΘΚΠ
the world > matter > physics > electromagnetic radiation > radio wave > [noun] > instrument measuring
riometer1958
1958 Geophysics & IGY (Amer. Geophysical Union) 51 They [sc. a team at the Geophysical Institute, University of Alaska] measure the ‘relative ionospheric opacity’ and name their instrument a riometer.
1959 C. G. Little & H. Leinbach in Proc. IRE 47 315/2 Thirteen of the commercially built units, now called ‘riometers’ (Relative Ionospheric Opacity Meters) are currently in use... The riometer is a self-balancing receiving system in which a local noise source is continuously made equal to the noise power from the antenna.
1972 Nature 28 Jan. 215/1 Ground based observations using a 27 MHz riometer and an H magnetometer indicated almost quiet ionospheric conditions.
2002 Geophysics in UK (Royal Astron. Soc.) 17 (table) An array of receivers acts as an imaging riometer to give a set of absorption values over an extended field of view.
This entry has been updated (OED Third Edition, June 2010; most recently modified version published online March 2022).
<
n.1958- to take a thing wherever one can get it
- to take a thing with one
- to take a toss
- to take a toy
- to take a toy at
- to take a toy to
- to take a tree to stall
- to take a tumble
- to take a tumble to oneself
- to take a turn for the
- to take a turn for the better
- to take a turn for the worse
- to take a turn in the parsley-bed
- to take a turn in the parsleybed
- to take a use of
- to take a view of
- to take a vizy
- to take a vote
- to take a walk
- to take a walk on the wild side
- to take a walk-out powder
- to take a walkout powder
- to take a wicket
- to take a woman's maidenhead
- to take a wooden nickel