Hydrology and Remote Sensing Laboratory : Helicopter remote sensing during the BOREAS experiment in Canada

Boreal Forest Reflectance Study Using a Helicopter Platform

	The Boreal Ecosystem Atmosphere Study (BOREAS) was conducted between the dates of May 24 and September 19, 1994 in Canada near Prince Albert, Saskatchewan and Thompson, Manitoba. The study was conducted in an attempt to reach a greater understanding of the land/atmosphere interactions in the Northern Boreal forest regions. With this greater understanding, scientists will be able to better estimate and predict how global change will affect us in the future. NASA's Global Change Master Directoryhas more information on global change research/issues.
	During BOREAS, remote sensing measurements were made on the ground, from a helicopter and other aircraft, and from satellites. Some of the instruments used on the helicopter were a Barnes Modular Multiband Radiometer (MMR) and a Spectron Engineering SE-590 spectrometer. Because the remote sensing signal even at low altitudes is affected by the atmosphere, a sun photometer was also used to allow for atmospheric corrections. Sun photometers measure the direct solar irradiance at the level they are operating at and their signal is used in converting at-sensor radiances to at-surface reflectances.
	The Boreal Forest in September 1994.
	Near Infrared reflectance as a function of Leaf Area Index (LAI) for three Boreal Forest tree species. The influence of change in LAI on near-infrared reflectance for these three tree species is markedly different. Notice that the three groups occupy mutually-exclusive areas in cartesian space.

For more information about this study go to http://boreas.gsfc.nasa.gov or
contact Dr. C. L. Walthall, Remote Sensing and Modeling Laboratory (cwalthal@hydrolab.arsusda.gov)