S.altern. DWV6a4-0511 gray.a

Spectrum Details

Modality

NIR

Category

vegetation

Material Type

PLANT

Sample ID

Spartina alterniflora at DWV6a4-0511

Collection Locality

Northern Barataria Bay, approximately 58 km south-southeast of New Orleans, 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 gray non-photosynthetic leaves and stems of smooth cordgrass (Spartina alterniflora). Plant leaves and stems were found in a mat on the surface of the marsh. The measurements were made on May 10, 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 of the mat of leaves and stems. The contact probe was pressed against the optically thick mat and a spectrum was recorded. Two measurements were made in each spot before moving the contact probe to a new position. 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