ObjectiveQuantum interference radar (QIR) is a promising technology that has been widely developed in modern warfare and civil fields. QIR is information transmission through quantum signals, and quantum signals are greatly disturbed by the transmission environment, so the detection efficiency will also be affected. When detecting photon transmission through the rainfall region, phase delay will occur, resulting in attenuation of quantum signal strength and energy reduction, and thus reducing the accuracy of QIR detection, such as ice crystal particles, tropospheric water clouds, raindrop particles, etc. However, until now, the effect of rainfall on QIR performance has not been studied. Therefore, it is very important to analyze the influence of light scattering characteristics of raindrop particles on QIR detection performance under different rainfall intensity.MethodsAfter linear superposition, raindrop particles of different sizes can still be regarded as spherical particles, similar to equivalent spheres. Firstly, the light scattering characteristics of raindrop particles are analyzed based on Mie scattering theory and Gamma distribution spectrum function. Secondly, according to the scattering characteristics, the energy attenuation of photons passing through the rainfall region is analyzed, and the relationship model between rainfall intensity and link attenuation and transmission distance is established. According to the parity operator detection method, the relationship between rainfall intensity and sensitivity and resolution is studied and analyzed for different pulse photon number and different emission wavelength, and simulation experiments are carried out.Results and DiscussionsThe extinction coefficient increases gradually with the increase of rainfall intensity (Fig. 3). Photon energy decreases with the increase of transmission distance, and the greater the rainfall intensity, the more obvious the photon energy attenuation trend (Fig. 4). Link attenuation increases with the increase of rainfall intensity and transmission distance (Fig. 5). The number of pulse photons has a great influence on the sensitivity and resolution of QIR. With the same number of photons, the sensitivity of QIR decreases with the increase of rainfall intensity; with the increase of photon number, the sensitivity of QIR increases with the increase of photon number when the influence of rainfall is small (Fig. 6). At the same photon number, the resolution of QIR decreases with the increase of rainfall intensity (Fig. 7); at the same incident wavelength, the resolution decreases with the increase of rainfall intensity, but the influence of wavelength on the resolution is not obvious (Fig. 8). In general, selecting the appropriate wavelength and increasing the number of pulse photons can effectively improve the performance of QIR detection.