Insect Monitoring Radar: Maximizing Performance and Utility

V Alistair Drake,Colin Symons,Shane Hatty,Haikou Wang

doi:10.3390/rs12040596

Abstract

Autonomously-operating radars employing the ‘ZLC configuration’ have been providing long-term datasets of insect flight activity to heights of about 1 km since the late 1990s. A unit of this type operating in Australia has recently received a major upgrade. The aim of the project was to maximize the utility of the radar to entomologists and aeroecologists by providing larger and more continuous datasets and extending observations to 2.5 km. The upgrade was achieved primarily by incorporating modern digital technology, which has enabled much improved data-acquisition, control performance, and data-archiving capacity; by implementing a more comprehensive observing protocol; and by replacing fixed electronic signal-acquisition gates with specially developed software that identifies insect echoes and applies a narrow moving gate that follows them. The upgraded version provides an approximately five-fold increase in hourly sample sizes, a doubling of the duration of observations (from 12 to 24 h per day) and a doubling of the height range over which observations are made. The design considerations (incentives and constraints) that informed the various subsystem implementations are identified, and the necessary compromises are discussed. Observations of the development of a layer echo during a migration by two different insect types are presented as a demonstration of the upgraded unit’s capabilities.

Highlights

Radars that are designed for long-term observations of insects flying at heights up to around 1 km were first deployed around 1990 [1]
As a more general example of the IMRU’s capabilities, observations of a nocturnal migration in which a distinct layer concentration developed and later dissolved (Figure 3)
With its ability to detect and characterize individual insects, as well as its consequent ability to partition the migrant population into different classes, it complements weather surveillance radars: while the latter scan over a wide area, they can provide information only about mixed ensembles of migrants

Summary

Introduction

Radars that are designed for long-term observations of insects flying at heights up to around 1 km were first deployed around 1990 [1]. Long-term data from these radars have led to advances in the understanding of migratory behaviour and its ecological consequences (e.g., [4,5]) and have provided support for operational pest forecasting [6]. The narrow beam, high range resolution, and short observing range of the IMRs and VLRs allow them to resolve individual insects, enabling the discrimination of different target types [8,9] and the examination of within-population variances of migration parameters (e.g., [10]). The relatively low capital and running costs of these units maRkeemottheeSmens.m20o20r,e12c,o5m96patible with the modest budgets typical of entomological and aeroec2oolof g21ical resepaorpcuhlaptrioongrvaamrisa.nces of migration parameters (e.g., [10]). Advs asunbtaugneitos fhiamvepargoevdedanpdecrofomremtaonnceeedand reliraebpilaiitry.oIrnrtehpelaccaesme oenf th, me IoMreRms oopdeerrantienqguiinpmAuenstrhalaisa,boepepnoirntturondituiecsedp,roevitihdeerdthbryonuegwh dnaetcae-sascitqyu―isaitsion techsunpoelorsgeideesdhcaovme pleodnetnotsa bmecoarme egeunnearvaalilraebvliee―woroftothteakseyastdevmans’tadgeesoigfnimapnrdovoepderpaetrifnogrmparontcoecaonlsd, as welrlelaiasbrielictyo.gInnititohne cthasaet oafnthIMe RIM’sResffoepcetirvaetinnegssinasAuasftaracliilait,yopfoprorotbusneitriveisnpgroinvsidecetd mbyignraetwiondactoa‐uld be accoqnusiisditeioranbtleychincorleoagsieesdh. avEexpleedrietoncaemgoarienegdentehrraolurgevhieawnaolfysthinegsyIMsteRmsd’adtaesfirgonmanodveorpearadtiencgade (e.gp.,ro[6to,1c0o,l1s1, a])sawlseoll iansfroercmogendittihonistrheavtiaenwIMbyR’isnedfifceactivnegnceisrscausmasftaacnilciteysfworhoebrseelravrignegrindsaetcatsmetisg,roartiomnore conctoinuuldobuescoobnsseidrveraatbiolyn,inwcroeualsdedli.kEexlpyehriaevneceegnaaibnleeddthadroduigtihonanaal loyrsisntgroInMgRerdsactaiefnrotimficoivnefrearednecceasd.eAn upg(er.agd.,e[d6,1u0n,1i1t,])daelssoiginnafotermd eIdMtRhiUs r(e‘vIMiewR bUypignrdaicdaetdin’g), cwircausmsustbasnecqeus ewnhtelyredlaervgeelrodpaetdasaentsd, odrempoloreyed to Hcoanyt,inNueowusSoobustehrvWatiaolnes, ,wAouusldtralilkiaely(3h4a.5v4e5e8n◦Sab, l1e4d4a.8d6d6i3ti◦oEn)a,lwohr esrtreointgceormscmieennticfiecdinofbesreenrvceast.ioAnns in Auugupgstra2d0e1d7.unit, designated IMRU (‘IMR Upgraded’), was subsequently developed and deployed to

Objectives

Results

Conclusion