Patent ID: 6921898
Filing Date: 2005-07-26
Classification: G01J,G01N

Abstract:
1. A radiance-related physical property determination method comprising: generating plural distinguishable images each being characterized by plural pixels, said generating including using an imaging device, each said image including a target and at least a portion of the natural hemispheric background, the atmospheric path between said target and said imaging device being characterized by path radiance, said natural hemispheric background being characterized by a hemispheric background radiance that illuminates said target, said hemispheric background radiance aiming toward the surface of said target from every hemispheric direction, said target being characterized by a target radiance and a target emission, said target radiance relation to the combination including said hemispheric background radiance, said target emission, and said path radiance; determining said target radiance and said hemispheric background radiance that correspond to each said image, each said determination being made with respect to a said image based on pixel intensities associated with the thermal character of said image, wherein said hemispheric background radiance varies in accordance with zenith angles θ and azimuth angles φ, said natural hemispheric background being characterized by said zenith angles θ and said azimuth angles φ, said zenith angles θ ranging between zero and 90 degrees said azimuth angles φ ranging between zero degrees and 360 degrees; and based on said determinations corresponding to said images, calculating a bi-directional reflectance distribution function of said target; wherein said calculating of said bi-directional reflectance distribution function includes effecting mathematical matrix inversion to obtain said bi-directional reflectance distribution function; wherein said mathematical matrix inversion is based on plural said relationships between said target radiance and said combination including said hemispheric background radiance, said target emission, and said path radiance; wherein each said image has at least one said relationship associated therewith for effecting said mathematical matrix inversion; wherein said mathematical matrix inversion is effected in relation to plural said images; wherein said relationship between said target radiance and said combination is mathematically expressed as wherein: the term (1−ρ)L the term corresponds to said hemispheric background radiance; L is said target radiance; τ(R) is the hemispheric atmospheric transmission; L T L L Φ is said azimuth angle; θ is said zenith angle; B is said bi-directional reflectance distribution function; ρ is the reflectance of said natural hemispheric background;