1987 Volume 23 Issue 1 Pages 5-10
In order to determine the true temperature of an object from the radiance temperature, correction for emissivity must be made. The area which corresponds to the field of view (FOV) of a radiation thermometer often includes two or more kinds of material. Then we have to know what kinds of material exist in the area and how large partition of the area is occupied by each of them.
In this paper we propose a method to determine the net radiance and the true temperature of the area.
Firstly, we determine the kinds of material in the area and the partition of the area occupied by each of them from the multispectral reflectance. Using these values of the partition, secondly we remove the effect of the radiation from environment reflected by the object. They enable us to correct the radiance temperature to obtain the true temperature of the object.
The basic idea of this method is that the total incident power into the thermometer is described by the linear sum of the contributions from each part of the area. The sum of the products of the radiance and the partition of each material in the area gives us the radiance of the area.
