Orbital perturbations in satellite communication pdf

Unsourced material orbital perturbations in satellite communication pdf be challenged and removed. Coverage of Earth by the Iridium satellites which are arranged in six orbits of 11 satellites each.

July 29, 1993, to November 1, 1998, when the system became operational and commercially available. The constellation consists of 66 active satellites in orbit required for global coverage, and additional spare satellites to serve in case of failure. Each satellite can have four inter-satellite links: one each to neighbors fore and aft in the same orbital plane, and one each to satellites in neighboring planes to either side. The satellites orbit from pole to same pole with an orbital period of roughly 100 minutes.

This design means that there is excellent satellite visibility and service coverage especially at the North and South poles. The over-the-pole orbital design produces “seams” where satellites in counter-rotating planes next to one another are traveling in opposite directions. Iridium supports inter-satellite links only between satellites orbiting in the same direction. This reduced set of six planes is sufficient to cover the entire Earth’s surface at every moment.

Because of the shape of the Iridium satellites’ reflective antennas, the satellites focus sunlight on a small area of the Earth’s surface in an incidental manner. The Iridium satellite constellation was conceived in the early 1990s, as a way to reach high Earth latitudes with reliable satellite communication services. It turned out that just 66 were required” to complete the blanket coverage of the planet with communication services. 1990s and the first telephone call was made over the network in 1998. However, although the system met its technical requirements, it was not a success in the market. Iridium as set by its parent company Motorola. US history at the time.