The Experimental Study On Spatial Scattered Characteristic Of Copper

Bidirectional Reflectance Distribution Function BRDF is a physical quantity that effectively describes the scattering distribution characteristic and spectral characteristic from optical material surface. It is mainly determinated by the surface roughness, dielectric constant, wavelength, angle and polarization etc. BRDF can be used to evaluate bi-directional reflection, absorption characteristic and radiation characteristic of all kinds of material surfaces in the waveband of visible light or infrared laser spectrum. It can reflect some characteristics of material surface, such as colors, texture, luster etc. So it is applied not only to the vegetation monitoring, soil resource remote sensing, monitoring the environment and climate, and suppressing the stray light etc, but also the bidirectional reflectance measuring information is used further the course of quantifying remote sensing is promoted. The global climate system is monitored at multiple angles. The performance of electronic visual displays is improved and the optical characteristics of each kind of the materials are determined.In the last century some developed countries (such as America, Germany, Japan and Canada), had set up measurement devices of BRDF. But in our country, the study of the object characteristics was later. At present, considering that our country has no measurement system of BRDF in multi-wavelength at high temperature, so the innovations for the study of measurement technique of spatial scattering characteristic in this paper are as follows:1. Improve the BRDF measurement system. We add the temperature-controlled system which can be adjusted by the bidirectional thyristor and microcomputer-controlled controller AL808 on the BRDF automatic measurement system. The ranges of temperature are from 25℃to 410℃and the spectrum regions of this system are in visible, near infrared, middle infrared and far infrared. The equipment can realize the measurement of hemisphere spatial scattering characteristic from material surface at different temperature.2. The experimental study on measuring spatial scattering characteristic of copper. The single reference measurement method is adopted (the reference sample is F4). The experiments of measuring the hemispherical scattering on copper material were accomplished at different temperature and the three factors (temperature, incidence angle and wavelength) which affect the BRDF are analyzed. Some valuable data are obtained.3. Build up the semi-empirical scattered models on copper surface at different temperature. The practical measurement values of BRDF on copper at different temperature and receiving direction are studied in detail. Applying genetic algorithm, the experimental data are fitted and the parameters are optimized. Several analytical models of scattering distribution characteristic on copper surface at different temperature are established.