Adaptive spectral sensor and methods using same

Inventors

Goldstein, Neil • Cline, Jason A. • Vujkovic-Cvijin, Pajo • Adler-Golden, Steven M. • Fox, Marsha J. • Gregor, Brian • Lee, Jamine

Assignees

Spectral Sciences Inc

Abstract

An adaptive spectral sensor, and methods of using the sensor. The sensor uses a programmable band pass transmission filter to produce both contrast signals, which discriminate specific target materials from background materials by comparing spectral signatures in hardware, and scene radiance spectra. The adaptive spectral sensor may measure one or more scene spectra and may form a spectral image. The sensor may automatically adjust to changing spectral, spatial and temporal conditions in the environment being monitored, by changing sensor resolution in those dimensions and by changing the detection band pass. The programmable band pass can be changed on-the-fly in real time to implement a variety of detection techniques in hardware or measure the spatial or spectral signatures of specific materials and scenes.

Core Innovation

The invention provides a hardware spectrally encoding sensor system for detecting specific properties of a radiance image of a scene. The system comprises a spectrograph that forms a dispersed image with multiple spectral components displaced along a dispersion direction, a programmable spatial mask that encodes filter functions on the dispersed image, and optical elements that direct the encoded dispersed radiation to a detector. The detector records the intensity transmitted through each mask, so the measurements correspond to inner products of the filter functions with the scene radiance spectrum.

The core measurement approach uses filter functions that select specific spectral pass bands and/or spatial locations, where each filter function emphasizes one or more specific properties of a target or analyte. Two or more measurements are produced by encoding a series of two or more filter functions successively, or by encoding two or more filter functions simultaneously on a spatial mask arrangement. The invention then compares two or more measurements using linear operations such as subtraction and ratios to produce a contrast signal indicative of the specific properties of the scene.

In some embodiments, the invention uses information about a range of possible spectral features in the scene to develop a set of spectral filter functions that provide a near-complete description of all possible spectral features, enabling detection of high-resolution spectral information with a small number of measurements. Spectral basis functions are encoded with the programmable spatial mask to measure inner products with the scene radiance spectrum, and a signal indicative of the specific physical property in the scene is produced.

Claims Coverage

The document provides three independent claims: clm-00001, clm-00026, and clm-00029. Across these claims, the inventive features center on hardware spectrally encoding using a programmable spatial mask, measuring inner products between spectral filter/basis functions and a scene radiance spectrum, and producing contrast or property-indicative signals using linear operations such as subtraction and ratios.

The claim set focuses on measuring spectrally encoded inner products in hardware using a spectrograph plus programmable spatial mask, then deriving a contrast or property-indicative signal by comparing measurements with linear operations such as subtraction and ratios. Additional coverage includes using prior information about the range of possible spectral features to create a near-complete set of spectral filter functions that enables high-resolution spectral detection with a small number of measurements.

Stated Advantages

Documented Applications