Compass including means for displaying constellation data
US5269065A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1993 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Mar 19, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04G9/0076
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A compass wherein positional information regarding a predetermined terrestrial location is stored; present time, corresponding to the terrestrial location whose positional information is stored, is measured and displayed; and constellation data is stored. A geomagnetism-detector is provided for detecting the direction of geomagnetism and for deriving azimuthal data therefrom. A constellation data display device is provided for reading out stored constellation data in accordance with the derived azimuthal data, the stored positional information, and the measured present time, and for displaying the readout constellation data. Declination data representing magnetic declination regarding the predetermined terrestrial location may be stored, and the derived azimuthal data may be corrected in accordance with the declination data, to thereby obtain corrected azimuthal data which represents a geographical direction, which corrected azimuthal data is used by the constellation data display device in reading out and displaying the constellation data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.