modis subsetting and visualization tool: bringing time-series satellite-based land data to the field...

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MODIS Subsetting and Visualization Tool: Bringing time-series satellite-based land data to the field scientist National Aeronautics and Space Administration www.nasa.gov

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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 15National Aeronautics and Space Administration

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