Longitude of the periapsis — In astrodynamics, the longitude of the periapsis (symbolized varpi) of an orbiting body is the longitude (measured from the point of the vernal equinox) at which the periapsis (closest approach to the central body) would occur if the body s… … Wikipedia
Longitude by chronometer — Longitude by Chronometer, known by mariners as Long by Chron , is an astronomical navigation method of calculating an observer s position on earth. The method gives the observer a position line on which the observer is situated. Usually the… … Wikipedia
Longitude prize — The Longitude Prize was a reward offered by the British government through an Act of Parliament in 1714 for a simple and practical method for the precise determination of a ship s longitude. The prize was administered by the Board of… … Wikipedia
longitude — Refraction Re*frac tion (r?*fr?k sh?n), n. [F. r[ e]fraction.] 1. The act of refracting, or the state of being refracted. [1913 Webster] 2. The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a… … The Collaborative International Dictionary of English
Mean longitude — In astrodynamics or celestial dynamics, mean longitude is the longitude at which an orbiting body could be found if its orbit were circular, and free of perturbations, and if its inclination were zero. Both the mean longitude and the true… … Wikipedia
History of longitude — The history of longitude is a record of the effort, by navigators and scientists over several centuries, to discover a means of determining longitude. The measurement of longitude is important to both cartography and navigation. Historically, the … Wikipedia
Mesure de la longitude — Jusqu au XVIIIème siècle, les marins savaient aisément mesurer la latitude, avec par exemple un sextant ou la nuit grâce aux étoiles, mais par contre il leur était jusqu à cet époque très difficile de mesurer la longitude. Les marins pouvaient… … Wikipédia en Français
Compass — This article is about the direction finding instrument used in navigation. For other uses, see Compass (disambiguation). A simple dry magnetic pocket compass … Wikipedia
Orbital elements — are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two body systems, where a Kepler orbit is used (derived from Newton s laws of motion and Newton s law… … Wikipedia
Orbital mechanics — A satellite orbiting the earth has a tangential velocity and an inward acceleration. Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other… … Wikipedia