P.austr. DWO-3-DEL-2c stem.a

Spectrum Details

Modality

NIR

Category

vegetation

Material Type

PLANT

Sample ID

DWO-3-DEL-2 Phragmites australis stems

Collection Locality

Bird's Foot delta of the Mississippi river, Louisiana

Spectral Purity

1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Sample Description

This spectrum is the average reflectance of 10 field measurements (using an artificial light source) of brown stems of Phragmites australis. The stems were found littering beach sand between green stands of the plant. Some of the stems showed signs of degradation, appearing gray in color with frayed ends. The reflectance measurements were made on August 14, 2010, using an ASD Field Spectrometer 3 (FS3) in reflectance mode, relative to a Spectralon reference panel. The contact probe attachement (an artificial light source with a restricted, 1 cm diameter, field of view) was used to measure the reflectance spectra of stacks of stems. After each recording, the contact probe was moved to a different stack of stems. An average spectrum was computed from the recorded measurements. The average spectrum was converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel. The first 50 channels(0.35 - 0.40 microns) in the spectral measurement show relatively high levels of noise. Project Background This site was measured as part of joint work between the USGS Denver Spectroscopy Laboratory and the Coastal Restoration Assessment Branch of the USGS National Wetlands Research Center, Baton Rouge. This spectrum was used in the following publication: Kokaly, R.F., Couvillion, B.R., Holloway, J.M., Roberts, D.A., Ustin, S.L., Peterson, S.H., Khanna, S., and Piazza, S.C., 2013, Spectroscopic remote sensing of the distribution and persistence of oil from the Deepwater Horizon spill in Barataria Bay marshes, Remote Sensing of Environment, Volume 129, Pages 210-230. http://dx.doi.org/10.1016/j.rse.2012.10.028 IMAGE_OF_SAMPLE:

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126