Side By Side Comparison of Natural and NIR Manned Aerial Photos

Side By Side Comparison of Natural and NIR Manned Aerial Photos

ES 771 Remote Sensing

Brian Bird, Jamie Harrington, Jack Faris
December 2016

Introduction

Near Hutchinson, KS there is a field amongst the others that has been recently planted in turnips for cattle to feed on. This field is also the location of a day of manned aerial photography by Brian Bird. Brian has both a normal Sony DSC-RX100M2 camera and an identical camera that is near infrared (NIR) capable, courtesy of Deon van der Merwe, which he is using to take the photos out of the window of his Piper PA-22 airplane, which is being piloted by Steve Stacey. The comparisons below show what the fields look like with the naked eye and with the NIR camera.

The field in question as seen from ground level a month after the original flight.

Photo Comparisons

All photo comparisons have a description underneath with the natural visible image on the left and the NIR image on the right. These are the images captured in flight by Brian Bird

A view of the turnip field from the Northeast

Another view of the turnip field from the Northeast

A view of the turnip field from the South

A view of the turnip field from the West

A view of the turnip field from the East

Another view of the turnip field from the East, this one further South.

A view of the turnip field from the North

A view of the Arkansas River with the surrounding timber.

A flood control canal on the Arkansas River at the edge of Hutchinson, KS.

The edge of the city of Hutchinson, KS.

Flyover of a country home outside of Hutchinson

LANDSAT Comparison

Landsat false-color composite of the Hutchinson area. This composite is made up of ETM bands 3,4, and 5 by Jamie Harrington. Black box indicates study area, as pictured below with annotations. The zoomed in study area is a subscene of image LC80290332016314LGN00 acquired on November 9, 2016. This is a false-color composite made from ETM bands 3, 4, and 5 color coded as blue, green, and red. The fallow fields and bare surfaces appear light grey to blue while actively growing vegetation is red, lavender or pink. The turnip field appears bright pink, with surrounding red fields which contain wheat and alfalfa.

Color-NIR Camera

The graph below shows the spectral response of the modified camera. It can be seen here that the camera is able to detect reflected light in the Near Infrared (NIR) range between about 690 and 770 nm. Active vegetation is highly reflective at wavelengths between 700 and 1400 nm. For comparison, the longest wavelength that humans are able to detect is about 700 nm. In order to conduct a more detailed analysis of images taken from this camera, each image will need to be divided up into its individual spectral bands. This was not done in this study.

Courtesy of Deon van der Merwe of Arrow Consulting LLC, Manhattan, KS

Conclusion

This project shows the value of being able to take this aerial photography, as it is in higher resolution than the Landsat images alone, as well as the fact that it can be done whenever it is needed, rather than wait for the Landsat imagery to be produced.

References

ES 771 Remote Sensing, Emporia State University, Professor Dr. James S. Aber, http://academic.emporia.edu/aberjame/remote/.

Remote sensing of the environment: An Earth resource perspective, 2nd edition, by John R. Jensen (2007) page 357 (fig. 11-1)

U.S. Department of the Interior, U.S. Geological Survey Earth Explorer, http://earthexplorer.usgs.gov/.

U.S. Department of the Interior, U.S. Geological Survey Global Visualization Viewer (GLOVIS), http://glovis.usgs.gov/.