System for detecting ice or snow on surface which specularly reflects light
US6069565A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1998 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Oct 9, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64F5/20
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A presence of a polarization altering substance on a specular surface is detected by transmitting light from a single strobed light source to the surface over a transmitting path and receiving the transmitted light from the surface. An intensity of the light is measured in both an optical non-isolator state and an isolator state by a same detector by delaying the non-isolated return light for a definite period of time before measuring it with the detector. The measured isolated and non-isolated intensities are converted to logarithmic form, range corrected, and compared to reference data established for the specific specular surface being investigated to detect the presence or absence of the polarization altering substance. Attenuation and backscattering effects of scattering and/or absorbing interference in the transmitted light are compensated so that the reference table is entered at the correct point. Using different intensities of transmitted light increases the dynamic range of the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.