Variable Speed Transient Feature Extraction Of Underwater Moving Target

In the modern naval battle,the automatic identification of underwater targets is one of the key technologies of weapon system intelligence,but with the development of intelligent equipment and vibration and noise reduction technology,making the underwater targets radiation noise is getting lower and lower,so to further improve the detection of underwater targets and improve the characteristics of the means of extraction has become a hot topic.The variable speed navigation signal of the underwater moving target reflects the change of the propeller speed during the state of target start?acceleration and deceleration.This change has transient characteristics,and it is difficult to be suppressed,it can represent the essential characteristics of the target,getting effective feature extraction through of its frequency changes,especially the conversion of the line feature into a point feature,Its beneficial to the detection of underwater moving targets in modern sonar system.This paper is based on relevant research,use of effective signal processing and image processing techniques to feature extraction of underwater moving targets.The paper is divided into three parts,Analysis and simulation of radiated noise in underwater moving targets;Research on morphological edge detection technology in Image preprocessing;Research on feature extraction of transient radiated noise in underwater moving targets.After analysis the time-frequency characteristics of the measured underwater moving targets,established a time-domain expression of the logarithmic frequency-modulated signal and superimposed the gaussian white noise.By computer simulation,The time domain expression conforms to the time-frequency characteristic of the measured signal.In the process of image preprocessing,For Canny?Soble?Roberts and other traditional edge detection operator in the edge of the underwater motion target speed signal edge gray scale edge detection results will appear the emergence of some small intermittent and isolated noise points,Researched the morphological edge detection algorithm and its improved algorithm,for the line in the figure,by computer simulation,the improve algorithm select the appropriate structural elements,after comparing the morphological combinations of operations,choose the best combination of the operation.Researched the feature extraction algorithm based on the random hough transform.Aiming at the problem of traditional random hough transform algorithm in the whole edge,This article has been improved the algorithm,by a certain distance constraint to judged whether or not the selected pair of points is converted.Finally,the algorithm is used for simulation and experimental data's feature extraction,got the physical characteristics of the underwater moving target——propeller speed change.These features are an important basis for judging underwater targets.