| West Boylston, MA |
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| County: Worcester |
State: MA |
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| Active Since: 2010 |
Observer: Johnson |
| Lat/Long: 42.3, -71.8 |
Landsat WRS Path/Row: 13/30 |
| MODIS TIle V/H: 0/0 |
MODIS Line, Samp: 0.00, 0.00 |
Site/Hive Description:
This is one of six hives placed in private apiaries in rural/suburban central Massachusetts that are being monitored as part of a USDA project. Colony performance is being monitored as part of the Area Wide Investigation by Dr. Jeff Pettis and others. The colonies are maintained by the individual beekeepers. Detailed information is not included here for privacy considerations. Scale:
The scale is a USDA/NASA electronic logging device, calibrated by W. Esaias and installed and maintained by USDA personnel. The resolution of the device is about 0.1 lb, and data are logged at 10 min to 30 min intervals. The logger is downloaded periodically, and forwarded to the HoneyBeeNet for analysis. The scales are recalibrated annually.
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MODIS Subset Data (from the ORNL DAAC)
Red dots are the average of all pixels with acceptable quality (see landcover extract below for area covered).
Blue dots are the center pixel only (point is not plotted if the pixel is of unacceptable quality). |
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| NDVI The Normalized Difference Vegetation Index (NDVI) is the ratio of the difference between visible (red) and infra-red (IR) wavebands to the sum of these bands.
NDVI = nir - red / nir + red
NDVI provides an indication of the amount and vigor of vegetated surfaces.
NDVI has been widely used with multiple generations of satellite data.
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EVI
The Enhnaced Vegetation Index (EVI) is a more complicated combination of wavebands compared to the more widely used index, NDVI. The advantage of this newer index is improved sensitivity in high biomass regions and reduction in atmospheric influences.
where,
pNIR = NIR reflectance
pRed = red reflectance
pBlue = blue reflectance
C1 = atmosphere resistance red correction coefficient
C2 = atmosphere resistance blue correction coefficient
L = canopy background brightness
G = gain factor
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The MODIS sensor on the Terra satellite platform provides us with 16-day composite measures of NDVI/EVI throughout the year. NASA distributes MODIS data from many of their distributed data centers.
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MODIS Land Cover
MODIS Data Subset Citation:
Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC). 2007. MODIS subsetted land products, Collection 4. Available on-line [http://www.daac.ornl.gov/MODIS/modis.html] from ORNL DAAC, Oak Ridge, Tennessee, U.S.A.. |
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