| With the new requirement for radar to get more information from the battlefield, radar automatic target recognition (RATR) as a new research area appeared in the 1960s. To learn about the characteristics of the radar target data is a prerequisite to RATR. So this dissertation process a lot of measured and simulated data, and make a detailed analysis on the characteristics of the radar echoes from jet planes, propeller-driven aircrafts and helicopters. The results can be used in RATR and lay the foundations for the future research.The development of high range resolution radar has given strong support to RATR. The high range resolution radar echo of plane target is denoted as one dimension range profile. However, range profile is sensitive to target aspect and hard to observe. This dissertation makes detailed research on the characteristics of high resolution range profiles (HRRPs). According to the scattering center model theory, the aspect sensitivity of HRRPs, its relationship with other factors and its evaluation methods are analyzed in detail. A method to improve aspect stability of HRRPs is proposed. In addition, the characteristics of radar echoes from propeller-driven aircrafts are discussed. Trough experiments the modulation effect of propeller echoes, its influence, the relationship between its influence and other factors are analyzed.Compared with jet planes and propeller-driven aircrafts, the radar echoes of helicopters have different characteristics. It is very urgent to solve the problem of detecting low-altitude, slow-speed and hovering helicopters. By the use of "Radar Target Backscattering Simulation Software" and through many flight mode and research mode experiments with the U.S.-made helicopter AH-64 as an example, a detailed analysis of helicopter echoes' time, frequency domain and time-frequency distribution characteristics is made. Finally, according to these features, a tentative plan to detect hovering helicopters is proposed.
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