The invention relates to the technical field of
electromagnetic spectrum monitoring and
signal processing, and discloses a low-altitude unmanned aerial vehicle
electromagnetic interference complexity early warning method and
system based on a fast FFT
algorithm. According to the method, space electromagnetic signals are collected in real time, FFT
frequency domain analysis is carried out to obtain spectrum data, unmanned aerial vehicle
signal frequency and power and left and right interference
signal frequencies and interference energy are extracted based on the spectrum data, the frequency
coincidence ratio and the energy
coincidence ratio are calculated in an unmanned aerial vehicle
system working
frequency band, and objective complexity is obtained through the product of the frequency
coincidence ratio and the energy coincidence ratio. And determining an
electromagnetic interference complexity grade by combining a preset grade division standard look-up table, and further outputting an
alarm signal and / or prompt information. The
system comprises an
electromagnetic signal acquisition unit, a
signal processing unit and an early warning output unit, wherein the
signal processing unit completes parameter extraction,
overlap ratio calculation, complexity calculation and grading output. According to the scheme, complexity grading evaluation with low calculation amount is realized, and the method is suitable for real-time early warning of a low-altitude unmanned aerial vehicle scene.