Analysis of Brightness Temperature Attenuation by Chaff Corridor Based on Millimeter-Wave Radiation Calculation

This article proposes a method for calculating the millimeter-wave (MMW) radiation of chaff corridor-target-sea scene. This method is used to analyze the attenuation of target brightness temperature (TB) by chaff corridor. First, a numerical method is proposed to obtain the facet model of chaff corridor, which is then combined with the facet models of sea and target obtained by the traditional method. Second, the ray tracing method is carried out to obtain the MMW radiation TB of the scene. In ray tracing, the emissivity, reflectivity, and transmittance of chaff corridor facets are calculated by the generalized equivalent conductor (GEC) method and the calculation method of reflection and transmission by a layered medium (RTLM). The emissivity and reflectivity of sea and target facets are calculated by their permittivity. Finally, to verify the correctness of the MMW radiation calculation method, a method for measuring the emissivity, reflectivity, and transmittance of chaff corridor is proposed. The TB of chaff corridor-metal plate and chaff corridor-ship-sea scenes is simulated and measured to analyze the TB attenuation caused by the chaff corridor. The results show that the calculation method is effective and the attenuation by the chaff corridor decreases with the increase of TB.