Ee: Ephemeris

Plural ephemerides (f-mr-dz)

A table giving the coordinates of a celestial body at specific times during a given period. Ephemerides can be used by navigators to determine their longitude while at sea and by astronomers in following objects such as comets. The use of computers has allowed modern ephemerides to determine celestial positions with far greater accuracy than in earlier publications.

The American Heritage® Science Dictionary Copyright © 2005 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

The GPS signal contains three components: a "pseudorandom code," ephemeris data, and almanac data.

Time-location analysis for exposure assessment studies of children ... by Palcisko, Gary J. / Environmental Health Perspectives