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Decoding MODIS Version 6 Quality Science Datasets using MODIS Python Toolbox for ArcGIS


Code Repository

MODIS Python Toolbox

Additional Information

MODIS Version 6 Products List

Contact

Contact: LPDAAC@usgs.gov

Labels

MODIS   ArcGIS  Python Toolbox   GeoTIFF  HDF   Quality  

Objective

NASA’s Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data products often require the user to manually apply a scale factor or binary decoding scheme to get true data values and/or quality information from science datasets. The purpose of the MODIS Python Toolbox for ArcGIS is to provide users with a simple and intuitive way to decode and interact with science datasets (SDS) and quality assurance (QA) SDS layers for MODIS products.

Example

Scale Factor Tool

  • Input
    • Raster dataset (MODIS SDS layer)
    • Scale factor*
    • Output location and name
  • Output
    • Outputs from the Scale Factor Tool are in GeoTIFF format at the same spatial coverage and resolution as the input raster dataset.

  
* NOTE: the scale factor is a user defined parameter. See MODIS product pages to determine the appropriate scale factor for your chosen MODIS SDS.

 

Decode Quality Tool

This tool currently (09/27/2016) decodes QA SDS layers for MODIS Version 6 products

  • Input
    • Raster dataset (MODIS QA SDS layer)
    • Output locations
    • Output name
    • MODIS product
    • Product QA SDS layer name
    • Bit Field to decode
  • Output
    • Depending on the Bit Field input, the tool will output a GeoTIFF for one or all bit fields. Each output is a thematic raster containing the bit values, pixel counts, and descriptions for the associated bit field. 
       

Prerequisites

The geoprocessing tools within the MODIS Python Toolbox can only be executed using ESRI’s ArcGIS software. The tools have been tested in ArcGIS Pro (1.3), ArcGIS for Desktop (10.3.1 & 10.4.1), and ArcCatalog (10.3.1).
Additional Python Package Installation Requirements:

  • ArcPy*
  • Requests**

* ArcGIS Pro (1.3), ArcGIS for Desktop (10.3.1 & 10.4.1) and ArcCatalog (10.3.1) have ArcPy preinstalled
** The Requests package comes preinstalled in ArcGIS Pro 1.3. For ArcGIS for Desktop 10.3.1 or 10.4.1, the Requests package will need to be installed for the python installation utilized by ArcGIS.
 

Estimated Time to Complete

Times will vary depending on the parameters selected. To completely decode a quality layer for any available product, completion times are typically between 5-10 minutes.

Procedures

To use the DecodeQuality geoprocessing tools in the MODIS Python Toolbox

  1. Download MODIS Version 6 (V6) data to your local drive. Options for downloading MODIS data can be found on the product pages or on the Tools page, accessible from the main menu bar on the LP DAAC website.
  2. Obtain MODIS Version 6 (V6) product from archive of distribution service
  3. Start ArcGIS Pro or ArcGIS for Desktop
  4. Click Add Data and select the MODIS V6 product HDF-EOS file
  5. Select the QA SDS layer for the product from the subdataset list.
  6. Export the QA SDS layer as a GeoTIFF*
  7. Add the MODIS Python Toolbox to the ArcToolbox Window
  8. Click into the Toolbox and select a tool
  9. Fill in the tool parameters
  10. Click OK to execute tool
  11. Add the output data to the ArcGIS session (not done automatically)

*If the HDF subdataset QA layer is used as the input into the tool, an anomalous shift in the output GeoTIFF will be present

Author(s)

Aaron Friesz

Innovate!, Inc., Contractor to the U.S.Geological Survey (USGS)