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- Tundra_orbit abstract "A Tundra orbit (Russian: "Тундра") is a type of highly elliptical geosynchronous orbit with a high inclination (usually near 63.4°) and an orbital period of one solar day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell. Synchronization with the solar day ensures that the satellite, viewed from a point on the ground, describes a predictable trajectory in the sky at the same time day after day, and moves at a moderate angular speed over the area of interest. The ground track of a satellite in a tundra orbit is a closed "figure-eight".These are conceptually similar to Molniya orbits which have the same inclination but half the period (about 12 hours). The only current user of tundra orbits is Sirius Satellite Radio, which operates a constellation of three satellites.[citation needed] The RAAN and mean anomaly of each satellite is offset by 120 degrees so that when one satellite moves out of position, another has passed perigee and is ready to take over.Tundra and Molniya orbits are used to provide high latitude users with higher elevation angles than a geostationary orbit. Neither the Tundra nor Molniya orbits are geostationary because that is possible only over the equator, so both orbits are elliptical to reduce the time that the satellite is away from its service area. An argument of perigee of 270 degrees places apogee at the northernmost point of the orbit. (An argument of perigee of 90 degrees would likewise serve the high southern latitudes. An argument of perigee of 0 or 180 degrees would cause the satellite to dwell over the equator, but there would be little point to this as this could be better done with a conventional geostationary orbit.)The Tundra and Molniya orbits use a sin−1 √4/5 ≈ 63.4° inclination to null the secular perturbation of the argument of perigee caused by the Earth's equatorial bulge. With any inclination other than 63.4 degrees or its supplement, 116.6 degrees, the argument of perigee would change steadily over time so that apogee would occur either before or after the highest latitude is reached.".
- Tundra_orbit thumbnail Qzss-45-0.09.jpg?width=300.
- Tundra_orbit wikiPageID "4662630".
- Tundra_orbit wikiPageRevisionID "591289926".
- Tundra_orbit hasPhotoCollection Tundra_orbit.
- Tundra_orbit subject Category:Earth_orbits.
- Tundra_orbit type Line108593262.
- Tundra_orbit type Location100027167.
- Tundra_orbit type Object100002684.
- Tundra_orbit type Orbit108612049.
- Tundra_orbit type Orbits.
- Tundra_orbit type Path108616311.
- Tundra_orbit type PhysicalEntity100001930.
- Tundra_orbit type YagoGeoEntity.
- Tundra_orbit type YagoLegalActorGeo.
- Tundra_orbit type YagoPermanentlyLocatedEntity.
- Tundra_orbit comment "A Tundra orbit (Russian: "Тундра") is a type of highly elliptical geosynchronous orbit with a high inclination (usually near 63.4°) and an orbital period of one solar day. A satellite placed in this orbit spends most of its time over a chosen area of the Earth, a phenomenon known as apogee dwell.".
- Tundra_orbit label "Orbite Toundra".
- Tundra_orbit label "Tundra orbit".
- Tundra_orbit label "Tundra-Orbit".
- Tundra_orbit label "Órbita Tundra".
- Tundra_orbit sameAs Tundra-Orbit.
- Tundra_orbit sameAs Orbite_Toundra.
- Tundra_orbit sameAs Orbit_tundra.
- Tundra_orbit sameAs Órbita_Tundra.
- Tundra_orbit sameAs m.0cg0sc.
- Tundra_orbit sameAs Q846805.
- Tundra_orbit sameAs Q846805.
- Tundra_orbit sameAs Tundra_orbit.
- Tundra_orbit wasDerivedFrom Tundra_orbit?oldid=591289926.
- Tundra_orbit depiction Qzss-45-0.09.jpg.
- Tundra_orbit isPrimaryTopicOf Tundra_orbit.
