MarshWater

Spectrum Details

Modality

NIR

Category

vegetation

Material Type

PLANT

Sample ID

water near CRMS121v69

Collection Locality

Coastwide Reference Monitoring System (CRMS) site 121 subplot v69. CRMS121 is located in southern Louisiana, approximately 37 kilometers southeast of New Orleans, Louisiana,in the western part of the Breton Sound hydrologic basin on the coast of the Gulf of Mexico.

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 12 field measurements of shallow water at the marsh edge. Some decaying vegetation was floating on the water's surface. The measurements were made on June 8, 2010. These spectra were made using an ASD Field Spectrometer 3 (FS3) in reflectance mode, relative to a Spectralon reference panel. The fiber optic was held at shoulder height while standing at the marsh edge and pointed approximately 20 degrees off-nadir in order to avoid sun-glint. 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 following channels were deleted from the spectrum (set to a value of -1.23e+34) because of atmospheric contamination or high levels of noise: 410-420, 768-796, 1002-1100, 1447-1622, 1651-1669, and 2077-2151 corresponding to wavelengths 0.759-0.769, 1.117-1.145, 1.351-1.449, 1.796-1.971, 2.000-2.018, and 2.426-2.500 Site Classification The area has been predominantly classified as intermediate marsh (see http://lacoast.gov/crms2/home.aspx). General Site Description The plot is located in southern Louisiana, approximately 37 kilometers southeast of New Orleans, Louisiana. It is in the western part of the Breton Sound hydrologic basin on the coast of the Gulf of Mexico. For additional information on the CRMS site see http://lacoast.gov/crms2/home.aspx 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: 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: in the site layout diagram, the subplot location near the measurement site is indicated by the matching number within the parentheses

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126