Measurement and Verification of Lightning Return-Stroke Velocities

Samantha TaborMatthew Jay

Genesis Langum

Mentor: Dr. Danyal Petersen

What Are We Investigating?

• We will be using a high speed camera and an avalanche photodiode array to estimate the two-dimensional velocity of lightning return strokes.

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How Will We Do This?

• Observations and data gathering via:– High speed camera– Avalanche photo diode array– Flat plate antenna (electric field)

• Data processing and viewing– Photron Fastcam Viewer 3– Waveform viewing application (DF32)

Avalanche Photo Diode

High Speed Camera Flat Plate Antenna

How Will We Do This?

• Combine this with LMA data and possibly lightning detection network– Provides linear velocities of lightning return-

strokes• Compare velocities to past calculations

Why Is This Important?

• Inconsistent return-stroke velocity measurements

• Further understanding of lightning behavior– Aid in future scientific discoveries

• Direct implication for other projects– Ex. Defense Advanced Research Projects Agency

(DARPA)– Ex. Better engineering of strike-prone equipment

Our Goals

• Analyze as many return strokes as time permits

• Have at least one example of positively-charged lightning

• Provide useful data for further study

Selected ReferencesBoyle, J. S., and R. E. Orville, 1976: Return stroke velocity measurements in multistroke lightning

flashes. J. Geophys. Res,, 81(24), 4461-4466.

Chowdhuri, et. al., 2003: Parameters of Lightning Strokes: A Review. IEEE Trans. Power Delivery, 20(1), 346-358, doi:10.1109/TPWRD.2004.835039.

Idone, V. P., and R. E. Orville, 1982: Lightning return stroke velocities in the thunderstorm research international program (TRIP). J. Geophys. Res., 87(C7), 4903-4915.

Mach, D., and W. D. Rust, 1989: Photoelectric return stroke velocity and peak current estimates in natural and triggered lightning. J. Geophys. Res., 94(D11), 13237-13247.

Nakano, et al., 1988: Measurements of the Velocity Change of a Lightning Return Stroke With Height. Proc. 1988 International Aerospace and Ground Conf. on Lightning and Static Electricity, Oklahoma City, OK, National Oceanic and Atmospheric Administration, 84-86.

Rakov, V., 2007: Lightning return stroke speed. J. Lightning Res., 1, 80-89.

Wagner, C.F., 1963: The Relation Between Stroke Current and the Velocity of the Return Stroke. IEEE Trans. Power Appar. Syst., 82, 609-617, doi:10.1109/TPAS.1963.291375.

Any Questions?