Design of fast digital spectrum stabilization method for UAV radiometry system

The drone radiation measurement system has a sharp increase in demand for environmental radiation monitoring due to its easy manoeuvrability, low aerial survey cost, high patrol efficiency and no personnel safety concerns. In order to adapt to the fast, flexible and efficient characteristics of the drone, the detector for the Unmanned Aerial Vehicle (UAV) radiation measurement generally consists of a plurality of small-sized detectors to form a detection array. Due to the low single crystal count rate and the influence of electronic system temperature and packaging, many detectors of the UAV radiation measurement system will have "spectral drifts", which affects the quality of the synthesized spectrum and affects the accuracy of the whole system. Aiming at the characteristics of UAV spectrum measurement system, a three feature point recognition model is established, and the K-40 feature peak (1.46MeV) is approximated by reverse piecewise summation. Thus, the backscattering peaks and characteristic peaks K-40 of the measured spectrum can be obtained to achieve fast spectrum stabilization. Finally, through Gaussian Mixture Model (GMM) peak estimation and experimental validation, the method can obtain the characteristic peak position accurately, and the time between instrument start-up and automatic spectrum stabilization is less than 2 minutes.