Vertical Looking Radar (VLR) and the Remote Sensing of

Insects

By: David Golon December 1, 2009

Table of Contents

•Abstract

•Introduction

•Theory and Application

•Results

•Discussion

•Future Work

•References

Abstract As annoying blips on a radar screen, agricultural pests,

ecological links, or vectors for disease and parasites, insects comprise a huge part of our world. A fact exemplified by the fact that there are approximately 10 quintillion individual insects alive on the planet right now. The study of insects (known as entomology) is an age old prospect, yet many areas of entomology are still in their infancy. Any tools available to help us elucidate the complex lives and behaviors of insects would be a great asset to science. One of these tools is Vertical Looking Radar (VLR) which can help us continuously view insects in the atmosphere; something that in the past was impossible to do.

Introduction: BackgroundMany of the 900,000 species of known insects actively migrate at some point in their lifetime. Right now millions of metric tons of insects are traveling through the earths atmosphere.

Insect migrations can be vast- covering countries and continents. Yet without adequate flying speeds (often below 3 m/s) many migrating insects use the wind to aid in their migratory movements. (slide 5)

These migrations are by no means constant throughout time. Insects migrate due to changing favorability of feeding and breeding habitats.

Insect migration can be predicted spatially by the seasonal winds in certain climactic zones such as trade winds and monsoon winds. But ephemeral weather systems, which are comprised of much less powerful winds, can displace insect swarms away from their usual destination (Slide 6).

In temperate zones the variability in wind cause very complex migration patterns. (Slide 7)

pales weevil, Hylobius pales

Introduction: Useful RS TechnologyVLR: Vertical Looking Radar.

Vertical looking Radar, as the name implies is a radar beam pointed straight up. The plane polarized beam is offset from the vertical by a very slight angle and rotated to crate a nutation in the signal. (Slide 9)

In the two VLR systems that are currently in use the detected backscatter is separated into 15, 45 meter deep, range gates separated by 26 meters each, between 150 and 1166 meters above the ground. The data is collected over a 5 minute period and analyzed during a 10 minute non-sampling period. (Slide 10)

Analysis by Fourier Transform may either converge to a solution, in which case it is recorded, or yield unidentified an return signal, in which case the return signal is discarded. (Slide 11)

The analysis also uses return signals to create a simulated signal which is compared to the actual signal and used to give a quantitative estimate of the systems accuracy.

A) The distribution of return signals identified as insects and their reliability as opposed to the return signals that are assumed to be causes by rain or atmospheric moisture, designated as fails.

B) the distribution of correlation coefficients during a period of inclement weather.

Theory and Application

• The In-Situ Approach

Studies of insect migration primarily rely on data obtained by various, direct trapping techniques. (Slide 13 and 14)

- Light traps- Suction traps- Aerial nets suspended by balloon- Other ground based observations

The insects obtained by these in situ techniques are often manually identified to a pre determined taxonomic level and recorded, being incorporated into different long term studies.

Lingren Trap

Theory and Application

If a VLR signal is interpreted as an insect it will give three useful values about the target body.

1. Horizontal Speed2. Displacement Direction3. Body Orientation (Slide 16)

The returned backscatter signal from the VLR can be used to calculate a greater array of values, including:

1. Target Mass (Slide 17)2. Maximum Range for Analysis (Slide 18 and 19)3. Sensed Volume (Slide 20)4. Aerial density (Slide 21)

• What Vertical Looking Radar (VLR) can give us.

Body Orientation

ResultsSome Values coinciding with aforementioned variables as stated in the literature

Results

Results

Results

Discussion

• In July 2001 the vertical looking Radar system recorded roughly 45,000 insects above a 15 meter wide column.

• This data suggests that 30,000,000 large insects fly through each kilometer area of sky on an average summer month.

• Yet, aerial net trapping data suggests for every detectable insect there are at least another 100 too small for the radar to detect.

Discussion• As compared with previous technology the

Vertical Looking Radar System provides us with non-labor intensive, continuous in depth data sets that have revealed a great deal about high altitude insect biodiversity.

• Despite the great deal we have and could learn from these systems there are relatively few of them actively in use.

• The two VLR systems that were researched for this presentation are located in Rothamsted, Harpenden, Hertfordshire and Malvern, Worcestershire.

Future Work

• Arial Nets• X-Band Scanning Radar• Vertical Looking Radar (VLR)• Bistatic (Duel Dish) VLR

High Altitude migrational studies:

Then, Now, and Tomorrow

The Pied Piper Insect Conundrum

ReferencesChapman, J.W., Reynolds, D.R., Smith, A.D., (2003) Vertical Looking Radar: A New

Tool for Monitoring High-Altitude Insect Migration. BioScience 53 no. 5: 503-511

Chapman, J.W., Smith, A.D., Woiwod, I.P., Reynolds, D.R., Riley, J.R., (2002) Development of Vertical Looking Radar Technology for Monitoring Insect Migration. Computers and Electronics in Agriculture. 35: 95-110

Chapman, R.F., Joern, A., (1990) Biology of Grasshoppers. The United States of America. John Wiley and Sons Inc.

Hay, S.I., Packer, M.J., Rogers, D.J., (1997) The Impact of Remote Sensing on The Study and Control of Invertebrate Intermediate Hosts and Vectors for Disease. Int. J. Remote Sensing 18 No. 14: 2899-2930

Nord, J.C., Ragenovick, I., Doggett, C.A., (1997) Pales Weevil. [online] U.S. Department of Agricultural Services. [Cited on Nov. 29, 2009] Available from: http://www.na.fs.fed.us/SPFO/pubs/fidls/pales/fidl-pales.htm

Numbers of Insects (Species and individuals). [online]. Encyclopedia of the Smithsonian. [Cited on Nov. 27, 2009] Available from: http://www.si.edu/Encyclopedia_SI/nmnh/buginfo/bugnos.htm

Taylor, L.R., (1974) Migration, Flight Precocity and the Boundary Layer. Journal of Animal Ecology. 43 No.1: 225-238

Video courtesy of Dr. James Lashomb, Professor of Entomology, Rutgers University, N.J. Direction/Film/Editing: Daniel Jusino, Talent: David Golon, Tim Freiday

Indirect ReferencesAldous, A.C., (1990) An Investigation of the Polarization Dependence of Insect Radar

Cross Sections at Constant Aspect. Ph.D. Thesis, Cranfield Institute of Technology, Cranfield, UK

Beerwinkle, K.R., Lopez, J.D. Jr., Witz, J.A., Schleider, P.G., Eyster, R.S., Lingren, P.D., (1994) Seasonal Radar and Meteorilaogical Observations Associated with Nocturnal Insect Flights at Altitudes to 900 Meters. Environmental

Entomology. 23: 676-683

Bent G.A., (1984) Developments in Detection of Airborne Aphids with Radar. Pages 665-674 in 1984 British Crop Protection Conference, Vol. 2: Pests and

Diseases. Croydon, UK: British Crop Protection Council

Drake, V.A., Farrow, R.A., (1988) The Influence of Atmospheric Structure and Motions on Insect Migration. Annual Review of Entomology. 33:183-210

Drake, V.A., Gregg, P.C., Harman, I.T., Wang, H.K., Deveson, E.D., Hunter, D.M., Rochester, W.A., (2001) Characterizing Insect Migration Systems in Inland Australia with Novel and Traditional Methodologies. Pages 207-233 in

Woiwood, I.P. Reynolds, D.R. Thomas, C.D., eds. Insect Movement: Mechanisms and Consequences. Wallingford, United Kingdom: CABI Publishing

Indirect References:Continued

Reynolds, D.R., Riley, J.R., (1997) The Flight Behavior and Migration of Insect Pests: Radar Studies in Developing Countries. Chatham, United

Kingdom: Natural Recourses Institute. NRI Bulletin no. 71

Riley, J.R., (1985) Radar Cross Section of Insects. Proceedings of the National Institute of Electrical and Electronics Engineers. 73: 228-232

Riley, J.R., Reynolds, D.R., (1986) Orientation at Night by High-Flying Insects. Pages 71-87 in Danthanarayana, W., ed. Insect Flight: Dispersal and Migration. Berlin: Springer-Verlag

Skolnik, M.I., (1970) Introduction to Radar Systems. McGraw-Hill, London

Smith, A.D., Riley, J.R., Gregory, R.D. (1993) A Method for Routine Monitoring of the Aerial migration of Insects by using a Vertical Looking Radar. Philosophical Transactions of the Royal Society, B. 340: 393-404

Smith, A.D., Reynolds, D.R., Riley, J.R., (2000) The Use of Vertical Looking Radar to Continuously Monitor the Insect Fauna Flying at Altitude Over

Southern England. Bulletin of Entomological Research. 90: 265-277