Shadow Effect for Small Insect Detection by W-Band Pulsed Radar

Abstract

In radar entomology, one primary challenge is detecting small species (smaller than 5 cm) since these tiny insects reflect radiation that can be poorly observable and, therefore, difficult to interpret. After a literature search on radar entomology, this research found few works where it has been possible to sense insects with dimensions smaller than 5 cm using radars. This paper describes different methodologies to detect Mediterranean fruit flies with 5–6 mm sizes using a pulsed W-band radar and presents the experimental results that validate the procedures. The article’s main contribution is the successful detection of Mediterranean fruit flies employing the shadow effect on the backscattered radar signal, achieving an 11% difference in received power when flies are present. So far, according to the information available and the literature search, this work is the first to detect small insects less than 1 cm long using a pulsed radar in W-Band. The results show that the proposed shadow effect is a viable alternative to the current sensors used in smart traps, as it allows not only detection but also counting the number of insects in the trap.

Systematic challenges and opportunities in insect monitoring: a Global South perspective

“…On the other hand, direct detection methods involve a more immediate and targeted approach to studying insect populations [ 96 ]. Vertical-looking radar (VLR) systems, capable of autonomously monitoring insect migration patterns, offer detailed information on the shape, mass, altitude and movement of individual flying insects [ 102 , 103 ]. This transformative technology has been instrumental in quantifying seasonal and diurnal patterns of insect migration for various taxa.…”