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Originally built for PrimeStar, DirecTV acquired the satellite in its 1999 buyout of the company. [36] The satellite was relocated from 119° W to 72.5° W in 2004 and temporarily leased to Telesat for their Canadian BSS service. [37] [38] In July 2005, the satellite replaced DirecTV 6 at 110° W, where it has remained ever since. [21]
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 value of a solar beta angle for a satellite in Earth orbit can be found using the equation = [ + ()] where is the ecliptic true solar longitude, is the right ascension of ascending node (RAAN), is the orbit's inclination, and is the obliquity of the ecliptic (approximately 23.45 degrees for Earth at present).
The T14 satellite is the sixth satellite built by SSL (Space Systems/Loral) for operator DirecTV. The high-capacity spacecraft is based on the SSL 1300 platform, T14 is a 20-kilowatt class Ka-band and reverse-band digital broadcast satellite that will be used to deliver Ultra HD and other new consumer services for DirecTV.
This corresponds to an inter-satellite spacing of approximately 73 km. The major consideration for spacing of geostationary satellites is the beamwidth at-orbit of uplink transmitters, which is primarily a factor of the size and stability of the uplink dish, as well as what frequencies the satellite's transponders receive; satellites with ...
For an ideal uniformly illuminated parabolic reflector and θ in degrees, k would be 57.3 (the number of degrees in a radian). For a typical parabolic antenna, k is approximately 70. [14] For a typical 2 meter satellite dish operating on C band (4 GHz), this formula gives a beamwidth of about 2.6°.
The following formulas can also be used to approximate the solar azimuth angle, but these formulas use cosine, so the azimuth angle as shown by a calculator will always be positive, and should be interpreted as the angle between zero and 180 degrees when the hour angle, h, is negative (morning) and the angle between 180 and 360 degrees when the ...
The angle is measured eastwards (or, as seen from the north, counterclockwise) from the FPA to the node. [2] [3] An alternative is the local time of the ascending node (LTAN), based on the local mean time at which the spacecraft crosses the equator. Similar definitions exist for satellites around other planets (see planetary coordinate systems).