Quantitative ornithology with a commercial marine radar: standard‐target calibration, target detection and tracking, and measurement of echoes from individuals and flocks

Urmy, Samuel S.; Warren, Joseph D.

doi:10.1111/2041-210x.12699

Cited by 26 publications

(57 citation statements)

References 25 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Radar systems are valuable tools for the monitoring of aerial animal movements, but the results may suffer from important biases when the registered data is not processed adequately. In line with recent publications which detail adequate procedures (Schmaljohann et al 2008, Drake and Reynolds , Larkin and Diehl , May et al , Urmy and Warren ) we hope that this publication will help to improve the scientific quality of radar monitoring.…”

Section: Discussionsupporting

confidence: 64%

“…The lowest two kilometres of the atmosphere host huge quantities of animal movements, often invisible to the human eye (Liechti and McGuire , Reynolds et al ), and there is an increasing interest to investigate the function and importance of the aerial habitat (Chilson et al , Bauer et al 2019). There are several methods to monitor the movements of animals in the airspace (Drake and Bruderer ), with radar being the predominant technology when it comes to quantifying biomass flows (Chilson et al ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

et al. 2019

View full text Add to dashboard Cite

Quantitative radar studies are an important component of studying the movements of birds. Whether a bird, at a certain distance from the radar, is detected or not depends on its size. The volume monitored by the radar is therefore different for birds of different sizes. Consequently, an accurate quantification of bird movements recorded by small‐scale radar requires an accurate determination of the monitored volume for the objects in question, although this has tended to be ignored. Here, we demonstrate the importance of sensitivity settings for echo detection on the estimated movement intensities of birds of different sizes. The amount of energy reflected from a bird and detected by the radar receiver (echo power) depends not only on the bird's size and on the distance from the radar antenna, but also on the beam shape and the bird's position within this beam. We propose a method to estimate the size of a bird based on the wingbeat frequency, retrieved from the echo‐signal, independent of the absolute echo power. The estimated bird‐size allows calculation of size‐specific monitored volumes, allowing accurate quantification of movement intensities. We further investigate the importance of applying size‐specific monitored volumes to quantify avian movements instead of using echo counts. We also highlight the importance of accounting for size‐specific monitored volume of small scale radar systems, and the necessity of reporting technical information on radar parameters. Applying this framework will increase the quality and validity of quantitative radar monitoring.

show abstract

Section: Discussionsupporting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The first attempts to quantify nocturnal bird migration were made with short‐range X‐band scanning radar (Eastwood , Drake and Bruderer ). In many countries, military and civil air traffic radar is used to study the spatial and temporal distribution of bird migration on a larger, often national scale (Sutter , Lack , Alerstam , Buurma , Ruhe 2000).…”

Section: Animal Distribution Numbers and Biomass In Time And Spacementioning

confidence: 99%

“…With the introduction of radar by the military during the Second World War it soon became obvious that radar could help fill gaps in our understanding of how flying animals use the airspace (Brooks , Lack and Varley , Buss , Sutter , Eastwood ). Since that time, many different types of radar (Table 1) have been broadly applied to study the ‘invisible parts’ of the movements of both birds and insects on a broader scale, primarily in Europe, North America, east Asia and Australia (Lack , Drury and Keith , Alerstam , Myres and Apps , Williams and Ying , Bruderer , b, , Drake and Reynolds 2012, Beason et al , Drake and Bruderer ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Perspectives and challenges for the use of radar in biological conservation

et al. 2019

View full text Add to dashboard Cite

Radar is at the forefront for the study of broad‐scale aerial movements of birds, bats and insects and related issues in biological conservation. Radar techniques are especially useful for investigating species which fly at high altitudes, in darkness, or which are too small for applying electronic tags. Here, we present an overview of radar applications in biological conservation and highlight its future possibilities. Depending on the type of radar, information can be gathered on local‐ to continental‐scale movements of airborne organisms and their behaviour. Such data can quantify flyway usage, biomass and nutrient transport (bioflow), population sizes, dynamics and distributions, times and dimensions of movements, areas and times of mass emergence and swarming, habitat use and activity ranges. Radar also captures behavioural responses to anthropogenic disturbances, artificial light and man‐made structures. Weather surveillance and other long‐range radar networks allow spatially broad overviews of important stopover areas, songbird mass roosts and emergences from bat caves. Mobile radars, including repurposed marine radars and commercially dedicated ‘bird radars’, offer the ability to track and monitor the local movements of individuals or groups of flying animals. Harmonic radar techniques have been used for tracking short‐range movements of insects and other small animals of conservation interest. However, a major challenge in aeroecology is determining the taxonomic identity of the targets, which often requires ancillary data obtained from other methods. Radar data have become a global source of information on ecosystem structure, composition, services and function and will play an increasing role in the monitoring and conservation of flying animals and threatened habitats worldwide.

show abstract

Performance test and verification of an off‐the‐shelf automated avian radar tracking system

May

Steinheim

Kvaløy

et al. 2017

Ecology and Evolution

View full text Add to dashboard Cite

Microwave radar is an important tool for observation of birds in flight and represents a tremendous increase in observation capability in terms of amount of surveillance space that can be covered at relatively low cost. Based on off‐the‐shelf radar hardware, automated radar tracking systems have been developed for monitoring avian movements. However, radar used as an observation instrument in biological research has its limitations that are important to be aware of when analyzing recorded radar data. This article describes a method for exploring the detection capabilities of a dedicated short‐range avian radar system used inside the operational Smøla wind‐power plant. The purpose of the testing described was to find the maximum detection range for various sized birds, while controlling for the effects of flight tortuosity, flight orientation relative to the radar and ground clutter. The method was to use a dedicated test target in form of a remotely controlled unmanned aerial vehicle (UAV) with calibrated radar cross section (RCS), which enabled the design of virtually any test flight pattern within the area of interest. The UAV had a detection probability of 0.5 within a range of 2,340 m from the radar. The detection performance obtained by the RCS‐calibrated test target (−11 dBm2, 0.08 m2 RCS) was then extrapolated to find the corresponding performance of differently sized birds. Detection range depends on system sensitivity, the environment within which the radar is placed and the spatial distribution of birds. The avian radar under study enables continuous monitoring of bird activity within a maximum range up to 2 km dependent on the size of the birds in question. While small bird species may be detected up to 0.5–1 km, larger species may be detected up to 1.5–2 km distance from the radar.

show abstract

Quantitative ornithology with a commercial marine radar: standard‐target calibration, target detection and tracking, and measurement of echoes from individuals and flocks

Cited by 26 publications

References 25 publications

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

Perspectives and challenges for the use of radar in biological conservation

Performance test and verification of an off‐the‐shelf automated avian radar tracking system

Contact Info

Product

Resources

About