SIMULATION OF SPECTRAL RADIANCE OF A DYNAMIC INFRARED SOURCE

An infrared source with spatially and temporally variable radiance is designed. It can be used to simulate any other infrared source simultaneously in two wavelength bands. The theoretical analysis of the real and simulator source is performed to define the design parameters. A series of the concepts are evaluated for their potential as infrared sources. A three-dimensional heat transfer computer program is used to predict the thermal behavior of the prototype glassy carbon waffle target. Tests are performed on this target which show that its thermal and radiation properties are in agreement with its predicted behavior. Glassy carbon waffle source is a good infrared radiator which can be used repeatedly at high temperatures. Measurements are described which show that the uniformity in the surface temperature can be maintained even when a scanning laser beam is used to deposit the energy on the target surface. The target surface is described analytically as a low pass filter. Its time constant is shown to depend on the target material and the temperature distribution in the target.