Using Web-based Tools for GIS-Friendly Satellite Imagery

Using Web-based Tools for GIS-Friendly Satellite Imagery

Lindsey Harriman

SGT, Contractor to the USGS EROS Center, Sioux Falls, South Dakota

**Work performed under USGS contract G10PC00044

U.S. Department of the Interior U.S. Geological Survey

Introduction • Lindsey Harriman

- Science Integration Task Manager, NASA LP DAAC • LP DAAC: Land Processes Distributed Active Archive Center • Partnership between the U.S. Geological Survey (USGS) and

the National Aeronautics and Space Administration (NASA) • Located within the USGS Earth Resources and Observation

Center (EROS) in Sioux Falls, South Dakota, USA • 1 of 12 NASA Earth Observing System Data and Information

System (EOSDIS) DAACs

• https://lpdaac.usgs.gov

More about the LP DAAC

• The LP DAAC processes, archives, and distributes land remote sensing data from: - Moderate Resolution Imaging

Spectroradiometer (MODIS) - Advanced Spaceborne Thermal Emission and

Reflection Radiometer (ASTER) - Selected NASA MEaSUREs products - Community Products

What is GIS-Unfriendly Satellite Imagery?

“Mismatched projections”

“Difficult file format”

“Too much data covers my AOI”

“Too much data to download”

“It takes lots of data to cover my AOI”

What is GIS-Friendly Satellite Imagery?

Choose your own projection

Choose your own file format

Subset data by location

Download the band(s) you need

Mosaic data on the fly

Web-Based Tools

• Global Data Explorer (GDEx) - https://lpdaac.usgs.gov/data_access/gdex

• MRT Web - https://lpdaac.usgs.gov/data_access/mrtweb

• TerraLook - https://lpdaac.usgs.gov/data_access/terralook

Global Data Explorer (GDEx)

• Funded through NASA ROSES 2005 ACCESS Program

• A collaboration between the LP DAAC and George Mason University's Center for Spatial Information Science and Systems

• A seamless data viewer providing access to multiple sources of digital elevation data sets

• Users can subset and download data by area of interest in multiple formats and projections

• http://gdex.cr.usgs.gov/gdex/

Available Data in GDEx

• ASTER Global Digital Elevation Model v2 • MODIS Land Cover Type (IGBP classification)

• NASA MEaSUREs SRTM (1 & 3 arc sec, Combined 1 arc sec)

• NGA SRTM (1 & 3 arc sec) • GTOPO 30 • NASA Blue Marble

GDEx Functions and Features

• Identify a pre-defined square or draw your own polygon area of interest (AOI)

• Pre-defined AOIs (county, state, country) • Advanced, on-the-fly processing

- Mosaic several tiles - Clip tile data, or mosaicked data, to AOI - Reformat to GeoTIFF, ArcASCII, or JPEG - Choose UTM or Lat/Long projection

• Preview data before download

GDEx Tile Limits

Product Tile mosaic limit ASTER GDEM 20

NASA SRTM 1 arcsec 36 NASA SRTM 3 arcsec 50 MODIS Land Cover 300

GDEx Granule Limits

MRTWeb

• Developed by the LP DAAC to provide services for tiled MODIS data products

• Multiple MODIS data products - Terra MODIS - Aqua MODIS - Combined MODIS products

• Web interface: https://mrtweb.cr.usgs.gov/

• API: http://lpdaacsvc.cr.usgs.gov/services/mrt-api/

Available Data in MRTWeb

• Most MODIS tiled products - Surface Reflectance - Albedo - Vegetation Indices - Land Surface Temperature - Fire - Leaf Area Index - Primary Productivity

MRTWeb Functions and Features

• Mosaic up to 50 tiles • Clip tile data, or mosaicked data, to AOI • Download only the spectral bands you need • API available – create your own programmatic

workflow

MRTWeb Functions and Features

• Choose format: - HDF, HDR, or TIFF - Download bundle also includes original HDF

• Choose Projection - Sinusoidal - UTM - Albers Equal Area - Polar Stereographic - Lambert Azimuthal - Geographic

Easily apply colormap Import results from MRTWeb

MRTWeb Tile Limits

• Orders for up to 50 tiles • Mosaicking of up to 50 tiles, reprojection, reformat, etc.

MRTWeb Tile Limits

TerraLook

• Joint project between USGS EROS and the NASA Jet Propulsion Laboratory (JPL)

• Designed to: - Provide satellite images that show changes in the Earth’s surface over time

- Allow users to make visual interpretations of these changes

Available Data in TerraLook

• Complete up-to-date inventory of ASTER images for the entire world

• Three Tri-Decadal Global Landsat Orthorectified epochs

• Images are: - Simulated natural color - Georeferenced JPEGs - Resampled, but resolution still near native

TerraLook Features and Functions

• Integrated into the USGS GloVis interface to search and download

• Availability of archived collections (through 2012)

• Images are bundled with: - Standards-compliant metadata - A world file - An outline of each image’s ground footprint

Questions?