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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: LeafySpurge Spurge-B1-Jul98 DESCRIPT


SAMPLE_ID: Spurge-B1-Jul98

PLANT_TYPE: Invasive herbaceous perennial weed

PLANT: Leafy spurge

LATIN_NAME: Euphorbia esula L.




Average reflectance for an area of grassland invaded by the invasive plant species leafy spurge (Euphorbia esula L.). The area measured was approximately 5 meters in diameter. The leafy spurge cover was approximately 60% (estimated visually). The remainder of the rocky soil was covered by mixed native grass and litter.

The spurge plants were 0.3 to 0.6 meters in height. The leafy spurge plants in the area had green leaves. Only a few plants had retained their yellow-green flower bracts. Fewer bracts were present in this area (Site B) compared to site A. The grass cover was dry, brown, and sensescent.

The spectra were collected with the head of the spectrometer pointed approximately at nadir, approximately 1 meter above the ground surface, while the operator walked through the area recording spectra. This average spectrum was computed from 36 individual recorded spectra (each recorded spectrum was an average of 30 measurements).

The spectra were measured on July 10, 1998.

This area of leafy spurge is situated on a southwest facing slope in an area that had been grazed by cattle. The general location is a rural area on the northern edge of the city of Golden, Colorado (GPS coordinates are 39 degrees 47.062 minutes N latitude, 105 degrees 14.425 minutes W longitude; Datum = WGS84).

The specific location (Site B) of the area from which this average spectrum was computed is 60 meters SE of the given GPS coordinates.

Sky conditions during the measurement were mostly clear with a few small, patchy clouds.

The area measured corresponds with the area measured for spectrum Spurge-B1-Oct97.

Related spectra were taken in this same area (Spurge-B2-Jul98 and Spurge-B3-Jul98).

Photos of the sample:










SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib05a r 11328 0.2-3.0µm 200

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