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DOCUMENTATION_FORMAT: PLANT
SAMPLE_ID: Juncus roemerianus at DWV1-0511
PLANT_TYPE: wetland rush, perennial graminoid
PLANT: Black needlerush, also known as needlegrass rush
LATIN_NAME: Juncus roemerianus Scheele
COLLECTION_LOCALITY: Northern Barataria Bay, approximately 58 km south-southeast of New Orleans, Louisiana
COLLECTION_LATITUDE: 29.468400 deg. N
COLLECTION_LONGITUDE: 89.931300 deg. W
DATUM: NAD83
ORIGINAL_DONOR: Raymond F. Kokaly, USGS
SAMPLE_DESCRIPTION:
This spectrum is the average reflectance of 7 field measurements (using an artificial light source) of green and brown leaves and stems of black needlerush (Juncus roemerianus). Measurements were made at locations close to the tips of the leaves, in order to incorporate both brown and green portions of the plants. The measurements were made on May 12, 2011.
These spectra were collected 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 bundles of leaves and stems. Plant stems and leaves in the top 30 cm of the canopy were bunched together. The contact probe was pressed against the optically thick bundle and a spectrum was recorded. 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.
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