Passive position determination using two low-earth orbit satellites
US6078284A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 1996 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Sep 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/18554
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for passively determining the position of a user terminal (for example, a mobile wireless telephone) in a low-Earth orbit satellite communications system. The system includes a user terminal, at least two satellites with known positions and known velocities, and a gateway (that is, a terrestrial base station) for communicating with the user terminal through the satellites. The method includes the steps of determining a range difference parameter and a range-rate difference parameter. A range difference parameter represents the difference between (1) the distance between a first one of the satellites and the user terminal and (2) the distance between a second one of the satellites and the user terminal. A range-rate difference parameter represents the difference between (a) a relative radial velocity between a first one of the satellites and the user terminal and (b) a relative radial velocity between a second one of the satellites and the user terminal. The position of the user terminal on the Earth's surface is then determined based on the known positions and known velocities of the satellites, the range difference parameter, and the range-rate difference param…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.