【摘要】 短时信号分析法是在声脉冲叠加法基础上 ,采用复指数模型参量法进行数据处理 ,使测量频段向低频延伸 .计算时引入既定极点大大提高了抗干扰能力 .通过参数优化的讨论和误差分析 ,保证了较高的测试精度 .在普通房间中对 2 .4m× 2 .4m超细玻璃棉进行实际测试的结果表明 ,其垂直入射反射系数与驻波管法测量结果较为吻合 ,斜入射测试结果与理论估算值基本一致更多还原

【Abstract】 A short time signal analysis method was presented for measuring the reflection coefficients at oblique incidence at free field. It is based on the acoustic pulse superposition method and the complex exponential analysis method, which can achieve a lower measuring frequency. The capability of anti interference can be improved by the introduction of a priori poles. The optimization of the parameters and the errors of the experiments were discussed which can ensure the better precision. The method was applied to the measurements of glass fiber material of 2.4 m×2.4 m in the frequency range of 1～5 kHz with the largest incident angle of 60° in a common room. The results show that the normal incidence reflection coefficient agrees with that of the standing wave tube measurement, while the oblique incidence measurement agrees with the theoretical estimation values.更多还原