FED/MAC Data

Needle Absorptance Characteristics

Needle reflectance and transmittance measurements were made in order to derive needle absorptance characteristics of red spruce (Picea rubens), eastern hemlock (Tsuga canadensis), cedar, balsam fir, and white pine. Surface directional radiances and reflectances were measured for the the leaf samples with a spectroradiometer (LICOR LI-1800 Spectroradiometer with an integrating sphere attachment).

Temporal Coverage

The time of LI-COR data acquisition was in September 1989 and September, 1990. Samples for the laboratory measurements were transported within 24 to 48 hours, and less than 96 h elapsed between the time of branch excision until the spectral measurement. Usually, this was less than 48 hours.

Instrument Description

A LI-COR LI-1800 spectroradiometer with external integrating sphere attachment was used in conjunction with the "Case 3" measurement procedures outlined by Daughtry et al. (1989) to derive the optical properties of red spruce (Picea rubens) and eastern hemlock (Tsuga canadensis).

The spectra were obtained at 10 nm increments throughout the visible and near infrared wavelength region (0.4 - 1.1 um) using the LI-COR spectroradiometer and an external integrating sphere. The diameter of the sample port is 14.5 mm with an illumination beam diameter of 11.4 mm.

Reference

Daughtry, C.S.T, L.L. Biehl, and K.J. Ranson. 1989. A new technique to measure the spectral properties of conifer needles. Remote Sens. Environ., 27:81-91

Data Available:

Principal Investigator:
Dr. Darrel L. Williams
Biospheric Sciences Branch, Code 923
NASA/Goddard Space Flight Center
Greenbelt, MD 20771
(301) 286-8860

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