altitude circle

altitude circle

[′al·tə‚tüd ‚sər·kəl]
(astronomy)
(electromagnetism)
A bright circle which surrounds the central dark portion of a plan position indicator display or photograph, and results from ground clutter.
References in periodicals archive ?
In fact, the TABULAR DATA OMITTED equal altitude circle covers a range about ten times greater than the latitude range in the table--1,050 miles.