周期性局部平稳过程双重谱图分析和测量

ANALYSIS AND MEASUREMENT OF DOUBLE FREQUENCY SPECTRA OF PERIODICALLY LOCALLY STATIONARY RANDOM PROCESS

摘要: 本文讨论一类特殊的局部平稳随机过程——周期性局部平稳随机过程的分析方法。介绍了局部平稳性检验的一种方法。指出用双重谱图来描述这类信号是合适的。讨论了这类信号双重谱图实用测量法。最后列举测量渔船商船辐射噪声双重谱图的例子,从其双重谱图中可反映出舰船的许多物理特性,如螺旋桨转速,叶片频,叶片数等。给舰船目标识别提供了有力的工具。

Abstract: This paper deals with analysis procedures of periodically locally stationary random process which is a specific class of locally stationary process. A method of local sta-tionariness test and a practical measurement procedure are diseussed. Double frequency spectra are applied to description of this kind of processes. In the end of this paper some examples of measuring double frequency spectra of radiative noise of merchant ship and fisher boat are listed. Various kinds of physical characteristics of ships, e.g. rotative velocity of propeller, number of blades, can be easily seen from their double frequency spectra. This method supplies a useful tool for recognition of ship objects.