Chirplet变换及其推广

Chirplet transform and its extension

线调频Chirplet变换是一种新的线性时频分析方法。文章在介绍线调频Chirplet变换的基础上,比较了短时傅里叶变换STFT、连续小波变换CWT和Chirplet变换在瞬时频率计算方面的优缺点。对二次调频Chirplet变换做了介绍,在线调频Chirplet变换和二次调频Chirplet变换的基础上,修改了核函数,对Chir-plet变换做了一定的改进,在一定程度上提高了某一类信号在时频域的分辨率。针对修改后的变换给出了一些算例,并给出了在石油勘探开发中利用改进后的Chirplet变换对沉积旋回信号进行分析的一些初步应用。

Chirplet transform is a new method for analysis of linear time-frequency. The traditional Chirplet transform is introduced and the merit and disadvantage of the Chirplet transform, STFT transform and CWT transform in computing instantaneous frequency are discussed. The quadratic Chirplet transform is also introduced. Based on the traditional Chirplet transform and the quadratic Chirplet transform, a modified Chirplet transform is obtained by modifying the kernel function in order to improve the resolution of some signals in the time-frequency domain. Some experimental tests on the modified Chirplet transform are made, and an application to analysis of signals of sedimentary cycles in petroleum prospecting and development is presented.