Co-deployed optical referencing for responsive dust-based sensing system
US7400394B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 2005 |
| Grant date | Jul 15, 2008 |
| Priority date | — |
| Expiry date | Jan 26, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/7773
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods for calibrating an optical detector. In one embodiment an optical reference apparatus includes a body having an outer surface. At least a portion of the outer surface has a reflectance that can vary. The optical reference apparatus is adapted to be deployed with a cloud of optical sensors and has a terminal velocity that is about the same as the terminal velocity of the sensors. Further, the variation of the reflectance can be caused by a rotation of the optical reference apparatus (caused by an aerodynamic member). The sensors may be made from porous silicon and the optical reference apparatus may include a retroreflector. The apparatus also provides a method of referencing an optical signal. The method includes deploying an optical reference apparatus with a cloud of sensors and detecting a variation in its reflectance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.