Tetrahedral multi-satellite continuous-coverage constellation
US4854527A · kind A · utility
Inventor
Key dates
| Filing date | Jul 19, 1985 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Jul 19, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/195
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An improved, optimized, four-satellite tetrahedral constellation using common period elliptic orbits is disclosed which provides continuous global coverage (i.e., any point on the earth can always maintain line-of-sight visibilty with at least one of the four satellites). The constellation consists of two satellites having perigees in one hemisphere, and two satellites having perigees in the other hemisphere. All satellites have a common period, and positive visibility angles can be maintained down to a constellation (or satellite) period of 27 hours. At higher altitudes (longer periods) both the minimum visibility angles and the mean visibility angles will tend to increase. Replication may be provided by overlaying arrays with convenient offset. The invention is applicable to any celestial body wherein two satellites have two periapses in one hemisphere and the other two satellites have periapses in the other hemisphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.