MODIS Subsetting and Visualization Tool: Bringing time-series satellite-based land data to the field...
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Transcript of MODIS Subsetting and Visualization Tool: Bringing time-series satellite-based land data to the field...
MODIS Subsetting and Visualization Tool:
Bringing time-series satellite-based land data to the field scientist
National Aeronautics and Space Administration
www.nasa.gov
Tammy Walker Beaty 2National Aeronautics and Space Administration
What is MODIS• MODerate Resolution Imaging Spectroradiometer
• Hyper-Spectral sensor onboard two satellites
(Terra and Aqua)
• Terra MODIS and Aqua MODIS are viewing the
entire Earth’s surface every 1 to 2 days, acquiring
data in 36 spectral bands or groups of
wavelengths
• http://aqua.nasa.gov/reference/visualizations.php
Tammy Walker Beaty 3National Aeronautics and Space Administration
MODIS data is great, but • Users (Field researchers) have some inconveniences
• Data Volume
• Accessibility
• Data Format
• Processing Time
• Working conditions
Tammy Walker Beaty 4National Aeronautics and Space Administration
What ORNL DAAC offers • MODIS Land Products in an easy-to-use format and size to characterize field sites
• MODIS Subsets for Selected sites (1147 MODIS Collection 5)
Data formatted in ASCII (7X7 km subsets) and GeoTIFF (25X25 km subset)
Selection by Site Search, Country, Continent or Land Unit, Network, IGBP Classification
• MODIS Subsetting and Visualization Tool for Any Location on the Globe
Site Selection from a pick list or by entering a site’s geographic coordinates
Area defining the site can be from 1 pixel up to 201 X 201 km
• Documentation
Tammy Walker Beaty 5National Aeronautics and Space Administration
Selected Sites & Global Tool Products • Time series plots of the selected product measurement
• ASCII file of the pixel values for the selected product along with quality information
• Average & standard deviations for the area selected
• A file that can be imported directly into GIS software
• A land cover grid (IGBP classification) of the area
• An estimate of heterogeneity (Shannon richness and evenness)
• Documentation
Tammy Walker Beaty 6National Aeronautics and Space Administration
MODIS Global Tool• http://daac.ornl.gov/modis/modis_subsets3.cfm
• Global Subsetting and Visualization Tool
Tammy Walker Beaty 7National Aeronautics and Space Administration
MODIS Global Tool, Step 1 - select Location
• http://daac.ornl.gov/cgi-bin/MODIS/GLBVIZ_1_Glb/modis_subset_order_global_col5.pl
Tammy Walker Beaty 8National Aeronautics and Space Administration
MODIS Global Tool, Step 2 - select data layer and subset size (LST and 100 X 100)
Tammy Walker Beaty 9National Aeronautics and Space Administration
MODIS Global Tool, Step 3 - select temporal range, provide email address, and submit
Tammy Walker Beaty 10National Aeronautics and Space Administration
MODIS Global Tool, Step 4 – order description and subset creation
Tammy Walker Beaty 11National Aeronautics and Space Administration
MODIS Global Tool, Step 5 – order summary and verification
Tammy Walker Beaty 12National Aeronautics and Space Administration
MODIS Global Tool, Step 6 – order notification and data retrieval
• Link to visualization and data
• Citation
Tammy Walker Beaty 13National Aeronautics and Space Administration
MODIS Global Tool, Data Files can be downloaded
• Each order page has links to
the data files (on http server)
• Help files explain contents
and format
Tammy Walker Beaty 14National Aeronautics and Space Administration
Resulting Data • Unique URL for each order:
• http://daac.ornl.gov/glb_viz_2/02Oct2008_16:28:25_348253391L35.958767L-84.287433S201L201_M
OD11A2/index.html
Tammy Walker Beaty 16National Aeronautics and Space Administration
Available MODIS Products• Surface Reflectance
• Surface Temperature
• Land Cover
• Vegetation Phenology (life cycle)
• NDVI/EVI (Normalized Difference Vegetation Index and Enhanced Vegetation Index)
• LAI / fPar (Leaf Area Index and Fraction of photo-synthetically active radiation absorbed by vegetation)
• Net Photosynthesis
• Annual NPP (Net Primary Production)
• Calculated Albedo (ratio of diffusely reflected to incident electromagnetic radiation)
• Reflectance – BRDF (bidirectional reflectance distribution function) adjusted
Tammy Walker Beaty 17National Aeronautics and Space Administration
MODIS Collection 5 – 1147 sites• http://daac.ornl.gov/cgi-bin/MODIS/GR_col5_1/mod_viz.html
• By Country, Land Unit, Network, IGBP Land use Classification
8-day, 16-day, or annual composite periods
1 km, 50 m, or 250 m resolution
Documentation
MODIS Products offered at ORNL-DAAC
Surface Reflectance
Surface Temperature
Land Cover
Vegetation Phenology
NDVI / EVI
LAI / fPAR
Net Photosynthesis
Annual NPP
Albedo (calc)
Reflectance – BRDF Adjusted