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Using RedEdge imagery to discover hidden details of the Pearl Harbor attack

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Share | 03/06/2020

Kelsey with the FireFLY6 PRO
Pete Kelsey with the BirdsEyeView FireFLY6 PRO getting ready to map the Eva Airfield in Oahu, Hawaii.

Drone-based multispectral cameras are often used to map and monitor large agricultural fields. However, their uses and applications go far beyond agriculture. Multispectral sensors capture the light reflected by objects and can be used to see vegetation variation related to much more than just crops. Conservationists and environmental managers use them to classify species of lichen, foresters use them to identify diseased trees, and pipeline companies use them to see changes in vegetation caused by leaks.

In previous posts, we discussed how multispectral imagery was used to uncover buried archeological features. But are there other pieces of history multispectral imagery can help bring to light?

Pete Kelsey from VCTO Labs was invited by National Geographic Channel to join historian Marty Morgan in an effort to uncover more details about the Pearl Harbor attack.

Equipped with the BirdsEyeView FireFLY6 PRO and the MicaSense RedEdge, Kelsey flew over a WWII abandoned airfield in Oahu, Hawaii hoping to find traces of the Japanese attack on Pearl Harbor, which could help historians understand how it was perpetrated.

“We were hoping to find evidence of the aircraft we knew were parked there on the morning of Dec 7, 1941, having been damaged by the Japanese air attack. Bullet damage to the tarmac or blast damage from a bombing attack.”

Kelsey picked the BirdsEyeView fixed-wing because it can cover larger areas in one flight and the MicaSense RedEdge because of its five spectral bands which allowed him to get information otherwise invisible to the human eye.

“Having spent 25 years in the Civil/Survey/GIS tech space I knew drones would change the world. Indeed they have. Since then the variety of sensors that a drone can deploy has exploded and I am curious about them all — particularly multispectral for precision agriculture.”

In only 2 hours Kelsey was able to process the data using PIX4Dmapper. He analyzed the imagery using different vegetation indices like OSAVI, NDRE, and NDVI, but it was in the CIR Composite layer that Kelsey found the damage to the tarmac.

RGB EVA Field
RGB overview of the Eva Airfield

The results showed distinct marks over one of the sides of the airfield where extreme damage was apparent. With this information in hand both Pete and Marty went to the area flown and identified the marks as the heat marks of a WWII aircraft burned in place on the Eva Airfield as part of the Dec 7, 1941 attack — something that was not documented before.

CIR EVA Field
CIR Composite of the Eva Airfield. Heat marks circled in yellow.

“Without the data the RedEdge provided we would have been forced to walk the entire airfield in search of evidence of combat, which is not a good use of time for surveyors, archaeologists, or even TV producers. The RedEdge provided actual discovery that we caught on film. Important evidence for historians and scientists. We never would have found the area of the burned aircraft without the MicaSense (now AgEagle) technology.”

A firm believer that the use of new technology can reshape entire industries, Kelsey continues to use drone-based sensors for different applications, including precision agriculture and archeology.

“Drone-based remote sensing is changing the world. Using the RedEdge in an innovative way — for archaeology — is not new but it is right up there with photogrammetry in terms of being a game-changer for archaeological research. I cannot wait to see how others try similar, outside the box, experiments with multispectral cameras. I’ll bet users will make discoveries while doing typical, multispectral flights in agricultural fields.”


This finding was part of the first episode of the NatGeo series Buried Secrets of WWII. The full episode can be watched here.

VCTO Labs specializes in the use of technology to uncover and provide compelling stories. For more information visit vctolabs.com

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