| 摘要 |
A method of daytime imaging in a range of thermal wavelengths (3-5 microns) which includes specularly reflected solar radiation. Mathematical processing serves to separate the thermal and specular reflection components based on Fresnel's equations which relate the thermal component to three variables: the total radiation intensity; the degree of polarization of the total radiation; and the degree of polarization of the specular reflection component. The first two of these variables may be measured by means of a photometer which is scanned across a target area, and a suitably oriented polarizing filter. The third variable can be calculated as a function of two other quantities: the angle of incidence of sunlight on the target object and the index of refraction of the target object. The first of these two quantities is calculable from time and geographical position data, while the second can be estimated with sufficient accuracy. Each calculation produces a single pixel, and a succession of such pixels is used to build up an image upon a CRT raster which is synchronized with the photometer scan.
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