Insect-Equivalent Radar Cross-Section Model Based on Field Experimental Results of Body Length and Orientation Extraction

Rui Wang,Kai Cui,Xiao Kou,Shuaihang Wang,Cheng Hu,Huafeng Mao,Zhuoran Sun,Weidong Li,Yunlong Li

doi:10.3390/rs14030508

Rui Wang, Kai Cui + Show 7 more

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https://doi.org/10.3390/rs14030508

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Abstract

Migratory insects constitute a valuable component of atmospheric and terrestrial biomass, and their migratory behavior provides abundant information for insect management and ecological effect assessment. Effective monitoring of migratory insects contributes to the evaluation and forecasting of catastrophic migration events, such as pest outbreaks. With a large-scale monitoring technique using S-band weather radar, the insect density is estimated based on the linear relationship between radar reflectivity and the average radar cross-section (RCS) of the insects. However, the average RCS model neglects the morphological and observation parameters of the insects, which reduces the estimation accuracy. In this paper, we established an insect-equivalent RCS model based on the joint probability distribution of “body length–incident angle”. Then, we observed and extracted the morphological and observational parameters of the migratory insects by conducting a 69-day field experiment, using a Ku-band fully polarimetric entomological radar, in Dongying, Shandong Province, China. Finally, combined with the experimental results and the simulated scattering characteristics of individual insects with different body lengths, the typical insect-equivalent RCS model was established. The RCS of the model fluctuates between 0.233 mm2 and 0.514 mm2, with different incident angles. Our results lay a data foundation for the quantitative analysis of insects by weather radar.

Highlights

Introduction iationsIn order to find a more favorable living environment, insects often need to migrate [1].Migrating insects are a crucial part of the migratory biomass in the atmosphere and even on land, and their migration provides abundant information for insect management and ecological effect evaluation [2]
The results show that the radar cross-section (RCS) of insects increases with an increase in size, and the RCS is related to the incident angle
In order to consider the influence of the morphological and observation parameters proposed in Equation (4), we introduced the body length and incident angle in Section 3.3 into Equation (12)

Summary

Introduction

Introduction iationsIn order to find a more favorable living environment, insects often need to migrate [1].Migrating insects are a crucial part of the migratory biomass in the atmosphere and even on land, and their migration provides abundant information for insect management and ecological effect evaluation [2]. The most rampant explosive pests in the world are migratory insects, and their migratory flight poses a serious threat to the grain yield of all countries. It is of great economic significance to effectively monitor migratory insects and establish an early warning system [3]. Due to their small size and high flight altitude at night, traditional monitoring methods, such as optical instrument observation and aerial netting, are not able to achieve effective monitoring [4]. Radar has become an effective method of detecting and tracking migratory insects, due to its all-day and all-weather working advantages [5].

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