For a given zenith angle, the scattered light contribution comes from well defined layer of atmosphere, which can be termed as an effective scattering height.
The effective scattering height depends on the ozone absorption coefficient and on the solar zenith angle, increasing as with each of these.
The effective scattering height will always be higher for shorter wavelength which is more strongly absorbed.
In telecommunication, the effective height of an antenna is the height of the antenna's center of radiation above the ground.
In principle, such a radiator should be as thin as possible, although thicker radiators improve the bandwidth and contribute to a taller effective height.
"Scan indicated probable effective height of twenty kilometers."
The new station will transmit at just only 1.2 watts (non-directional antenna with an effective height of antenna above average terrain of -2.6 metres.
Therefore, the dam's effective height is greater than the 10 feet (3.05 m) shown in its specifications.
The effective height of this heat barrage was two miles, or less.
A moat was a common addition to medieval fortifications, and the principal purpose was to simply increase the effective height of the walls.