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Definition of angles in the vertical plane of SLAR Geometry of an SLAR SLAR radar at ILA Berlin Air Show. Side-looking airborne radar (SLAR) is an aircraft, [1] or satellite-mounted imaging radar pointing perpendicular to the direction of flight (hence side-looking). [2] A squinted (nonperpendicular) mode is also possible.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military ...
For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern.
The most effective clutter reduction technique is pulse-Doppler radar with Look-down/shoot-down capability. Doppler separates clutter from aircraft and spacecraft using a frequency spectrum, so individual signals can be separated from multiple reflectors located in the same volume using velocity differences. This requires a coherent transmitter.
The first satellite placed in a geostationary orbit was Syncom 3, which was launched by a Delta D rocket in 1964. [14] With its increased bandwidth, this satellite was able to transmit live coverage of the Summer Olympics from Japan to America. Geostationary orbits have been in common use ever since, in particular for satellite television. [10]
The radio horizon of the transmitting and receiving antennas can be added together to increase the effective communication range. Radio wave propagation is affected by atmospheric conditions, ionospheric absorption, and the presence of obstructions, for example mountains or trees. Simple formulas that include the effect of the atmosphere give ...
A narrow-band channel, by definition, does not allow rapid changes in modulation. Since it is the change in a received signal that reveals the time of arrival of the signal (obviously an unchanging signal would reveal nothing about "when" it reflected from the target), a signal with only a slow change in modulation cannot reveal the distance to ...
A Molniya orbit (Russian: Молния, IPA: [ˈmolnʲɪjə] ⓘ, "Lightning") is a type of satellite orbit designed to provide communications and remote sensing coverage over high latitudes. It is a highly elliptical orbit with an inclination of 63.4 degrees , an argument of perigee of 270 degrees, and an orbital period of approximately half a ...