摘要
声呐、雷达和声达测量的运动介质反向散射波在补偿了能量衰减之后仍是非平稳随机过程。演化谱是描述它的良好手段,不平稳因子A_t(ω)和特征宽度B_L有重要意义。当与散射体积元对应的时间尺寸小于B_L时,反向散射过程的功率谱呈单峰特性;当超过B_L时,功率谱呈双峰特性。选用具有平缓变化的模糊度函数的发射信号,可以减弱不平稳因子的作用。
In this paper, we discuss the backscatte,ring wave of sonar, radar and sodar in moving medium, which is a non-stationary stochastic process even if its energy attenuation is compensating. The use of evolutionary spectra is a good approach to describe it, while both the non-stationary factor At(ω) and the characteristic width BL are significant. When the time interval corresponding to the volume element of the scatters is smaller than BL, we can suppose that the power spectrum displays a single hump characteristic, and when it is greater than BL, we may use the power spectrum which displays a bi-hump characteristic. The transmitted signal which has slow varying ambiguity function can reduce the ffect of At(ω).
出处
《声学学报》
EI
CSCD
北大核心
1989年第1期30-35,共6页
Acta Acustica
