Back to results
US 4,988,196 AGranted
Time domain Fraunhofer line discriminator
AssigneeSperry Marine Inc.
InventorLawrence H. Gilligan
Life of this patent
Estimating the term…
Abstract
A scanning spectrometer scans the spread spectrum of sunlight and low level luminescence or fluorescence past a slit to provide the spectrum scanned in the time domain. An image intensifier responsive to the light energy passing through the slit is gated on when Fraunhofer lines are coincident with the slit. A photodetector responsive to the image intensifier detects the intensified total energy within each Fraunhofer line.
Claims19
Apparatus for detecting low level light emanations masked in sunlight, said sunlight with said emanations having a spectrum, said spectrum including at least one Fraunhofer line, comprising:
- a slit,
- spreading means for spatially spreading said spectrum of said sunlight with said emanations,
- scanning means for scanning said spread spectrum with respect to said slit,
- gated sensor means responsive to light passing through said slit from said scanned spread spectrum, and
- gating means for gating said gated sensor means when said Fraunhofer line is coincident with said slit so that said gated sensor means can sense a spectral component of said masked light emanations corresponding to said Fraunhofer line passing through said slit.
2 more elements
Dependencies are inferred from the claim text.