Oak QUDU

Spectrum Details

Modality

NIR

Category

vegetation

Material Type

PLANT

Sample ID

CA01-QUDU-1

Collection Locality

Garden Valley area, in El Dorado county, approximately 60 km northeast of Sacramento, California

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 29 field measurements of a leather oak bush (Quercus durata). The measurements were made at 3 pm local time on September 5, 2001. These spectra were made using an ASD FullRange spectrometer (model 653) in reflectance mode, relative to a Spectralon reference panel. The bare fiber of the spectrometer was used to measure the reflectance spectra of the bush. The leaves were green and small (1 to 2 cm in length) and curled at the edges, probably due to water stress. The tops of the leaves were dusty. The bush was approximately 1 meter in height. On average the field of view of the spectrometer included 70% green leaves, 10% branches and stems, 15% shadows, and 5% background soil/rock/litter. The fiber optic cable was pointed at nadir and held 30 cm above the top of the plant and moved around during the measurement. The instrument was programmed to record 6 second averages of reflectance (thus, each recorded spectrum was an average of 60 individual measurements). An average spectrum was computed from the recorded measurements and converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel. Other samples of leather oak were also measured, near this one, and are included in this spectral library, sample names: CA01-QUDU-2 and CA01-QUDU-3. This spectrum was used in the following publication: Swayze, G.A., Kokaly, R.F., Higgins, C.T., Clinkenbeard, J.P., Clark, R.N., Lowers, H.A, Sutley, and S.J., 2009, Mapping potentially asbestos-bearing rocks using imaging spectroscopy, Geology Volume 37, pages 763-766. http://dx.doi.org/10.1130/G30114A.1 IMAGE_OF_SAMPLE:

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126