Automatic extraction of jet engine blade number based on joint time-frequency analysis of jet engine modulation signals

In this paper, we present an automatic method for extracting the jet engine features from the joint time-frequency (JTF) representation of jet engine modulation (JEM) signals. First, short time Fourier transform (STFT) was used for acquiring the JTF representation. After converting the STFT result into an image with RGB colors, the green component was extracted as a representative of the JEM component. Finally, the peaks detected from the extracted green component can represent the jet engine features. The approach proposed in this paper is significant because the overall procedures for extracting the jet engine blade number are not manual but automatically performed based on the image processing method. Application to simulated JEM signal demonstrated that the automatic feature presented in this paper improved the accuracy of JEM analysis and is expected to be efficient for real-time radar noncooperative target recognition (NCTR).