Method and system for the autonomous on-board determination of the position of a satellite
US5984238A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1998 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Feb 2, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64G1/365
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A system for autonomous on-board determination of the position of an earth orbiting satellite consists of a biaxially measuring earth sensor which defines the z-axis (yaw axis) of the satellite and of several biaxially measuring sun sensor measuring heads which are arranged on the satellite structure such that, with the exception of earth shadow phases, they supply a direction vector measurement. Out-of-plane movement of the satellite is propagated by means of a precise model of the satellite dynamics including natural disturbance forces and thrusts during maneuvers on board. In order to compensate sensor uncertainties and the effects of thermal deformations, the satellite orbit is precisely measured at regular intervals (approximately 3 months), and by means of this information, a calibration function (time function for a day) for compensating measured values is determined. The in-plane movement of the satellite is not only propagated, but the propagation is supported by measured data (estimation), and the effects of out-of-plane movement and thermal deformations are taken into account, by means of the data of the calibration function (k(t) or of the propagation out-of-plane movem…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.