被动毫米波辐射成像系统中的通道误差研究

Channel errors in passive millimeter-wave radiometry imaging system

在被动毫米波成像系统中,仪器的误差对系统性能有很大的影响,主要有天线误差和通道接收机误差。本文研究被动毫米波辐射成像系统中的通道误差对系统温度灵敏度的影响。通过对系统的通道滤波器的频率响应建模,对造成系统通道误差的各个误差源进行了理论的分析,并通过计算机仿真得到各个误差源对温度灵敏度影响。可知通道的带宽不一致对温度灵敏度影响很小,而中心频率、群延迟和初始相位的不一致却对温度灵敏度有很大的影响,这对通道误差的分配有很大的理论指导意义。

The errors of instruments have a large impact on the performance of the Passive Millimeter-wave Radiometry Imaging System. The error souces are mostly antanna errors and channel errors. The effect from Channel errors on the radiometric accuracy in Millimeter-wave Radiometry Imaging Systemis studied. Each error souce which results in the channel error is theoretically analysed after the modeling on the frequency response of the receiver. And the results of each error souce on the radiometrie accuracy are got by simulation, that is the impartiality of the central frequency, the impartiality of the group delay and the initial phase have a large impact on the radiometric accuracy except the impartiality of the belt. This is important for the distribution of the channel errors.