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DOCUMENTATION_FORMAT: PLANT
SAMPLE_ID: wrack at DWV1-0511
PLANT_TYPE: wetland grasses and rushes
PLANT: Black needlerush, smooth cordgrass, and others
LATIN_NAME: Juncus roemerianus Scheele, Spartina alterniflora Loisel. and others
COLLECTION_LOCALITY: Northern Barataria Bay, approximately 58 km south-southeast of New Orleans, Louisiana
COLLECTION_LATITUDE: 29.46844 deg. N
COLLECTION_LONGITUDE: 89.93142 deg. W
DATUM: NAD83
ORIGINAL_DONOR: Raymond F. Kokaly, USGS
SAMPLE_DESCRIPTION:
This spectrum is the average reflectance of 14 field measurements (using an artificial light source)
of wrack deposited on the marsh. The wrack consisted primarily of brown, non-photosynthetic leaves and stems of
black needlerush (Juncus roemerianus) and smooth cordgrass (Spartina alterniflora).
The measurements were made on May 12, 2011.
These spectra were made 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. The contact probe was pressed against the wrack material and a spectrum was recorded.
After recording a spectrum, the contact probe was moved to a different area of the wrack material. 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:
END_SAMPLE_DESCRIPTION.
COMPOSITIONAL_ANALYSIS_TYPE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
TRACE_ELEMENT_ANALYSIS:
TRACE_ELEMENT_DISCUSSION:
END_TRACE_ELEMENT_DISCUSSION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns