Simulation Of Stray Radiation Transmission Characteristic For Infrared Detecting System And Its Surroundings

In the engineering project, a large amount of infrared testing system work under very wicked thermal surroundings, such as the high and heterogeneous temperature field. The excessive temperature field will transform the heated surface inside the system into the source of infrared stray radiation, which will produce a great deal of noisy signal and severely interferes the normally working of the testing system.This text is based on the above studying background, some relevant research has been performed on the transmission of stray radiation which is produced by the hyperthermal surface and semitransparent radiometry. In addition the procedure of stray radiation transmission inside two infrared testing systems is carried out: the one is a detecting system inside a specific space, the other is a experimental testing system of transmittancy inside high temperature environment. There three main mission in this text:1) By applying the fundamental theory of Monte-Carlo, some improvement and development has been performed of the calculating program of the stray radiation transmission inside infrared, after the improvement of the program, its flexibility and adaptability is optimized, which has been applied in the subsequent calculating.2) By using the improved program, relevant simulation of a kind of infrared detecting system inside specific space has been performed. This text use three different methods in calculation the three kinds of stray radiation sources: the averaged temperature surface, the internal surface of covering and the optical window. By calculation the radiation from different sources, the main source and its transmission route, the distribution of stray radiation on the detecting surface has been obtained, all these conclusions has provided important reference for the restrain of the stray radiation inside the infrared testing system.3) This text has also analyzed the stray radiation transmission inside a experimental testing system, which is used for testing the transmittancy of solid material in high-temperature environment. In this test, the interfere of the stray radiation has been analyzed, the relativerelationship of different stray radiation source has been obtained, thus the main source of stray radiation has been found. In addition, the inhibition effect of three kind of restrain components has been discussed and testified, the three kind of the restrain components are extinction cylinder, reflective mirror and eclipser, their best geometric parameters and spatial position to restrain the stray radiation are finally testified.