Target Detection and Density Inversion of Migrating Insects Based on a Novel Scanning Insect Radar

‍ ‍China is the most important animal migration site in the world. Pests of rice， wheat， corn and other crops migrate a long distance for procreation and breeding in China， which seriously threatens the safety of grain production. Because insects mostly migrate at night， radar is the most effective tool to monitor migratory insects by the all-weather and all-time detection capability. Scanning insect radar is a typical system for monitoring migratory insects， which can calculate the quantitative distribution and density profile of migratory insects in scan space. However， traditional scanning insect radar uses the two-dimensional mechanical scanning configuration， which has discontinuous scanning space， low data rate and low resolution. So， it is difficult to accurately measure the amount and distribution of migrating insects. A new type of scanning insect radar is presented in this paper， which adopts the high-resolution phased array radar system of pitch electronic scanning and azimuth mechanical scanning. The proposed scanning radar could quickly scan a wide range of space （azimuth 0°~360° and pitch 5°~85°）， and obtain the exact quantitative distribution and density profile of migratory insects. Nevertheless， the quantitative distribution was mainly subject to the problem of weak and small insect target detection under strong clutter at low elevation-angle； and the density profile was mainly influenced by the calculation of equivalent radar scanning volume under the jump of beam position in pitch of phased array radar. Therefore， this paper further proposed a varying parameter VI-CFAR detection method based on static clutter map and a density estimation method based on radar scanning microelement volume units， and the effectiveness of these methods are verified by simulation and measured data. At present， the system has been deployed in the modern agricultural demonstration base in Dongying， Shandong to carry out business operation， which can obtain the fine spatial distribution and density profile of nocturnal migratory insects and has observed the height stratification and other scientific phenomena of migratory insects. Key support is provided by the phased array radar for the mechanical analysis of insect migration spatial structure.