HDFEOS Workshop IV September 19, 2000 MODIS Reprojection Tool

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HDF-EOS Workshop IV September 19,
2000MODIS Reprojection Tool

• presented by
• John M. Weiss, Ph.D.
• Department of Mathematics and Computer Science
• South Dakota School of Mines and Technology

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Introduction

• MODIS instrument launched recently
• MODIS data
• Integerized Sinusoidal (ISIN) map projection
• HDF-EOS file format
• MODIS Reprojection Tool software
• ISIN-modified GCTP
• Support for standard map projections
• Support for standard file formats
• User-friendly graphical user interface (GUI)

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Functional Requirements

• Ingest data in ISIN projection from HDF-EOS or
  multi-file (raw binary) formats
• Transform data to nine standard projections
• Allow spectral and spatial subsetting
• Allow three resampling options
• Produce data products in HDF-EOS, GeoTIFF, or
  multi-file formats
• Execution via user-friendly GUI or command line
• Support for UNIX and Windows platforms

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Major Software Components

• GUI (Tcl/Tk or Java)
• Resampler
• GCTP (modified to support ISIN projection)
• GeoLib
• HDF-EOS and HDF libraries
• GeoTIFF and TIFF libraries
• Multi-file I/O Code
• Parameter File I/O Code

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Modules and Data
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Accomplishments

• Resampler processes 2-D gridded MODIS data
  products (Level-3)
• Handles multi-file, HDF-EOS, and GeoTiff file
  formats
• Supports all required map projections
• Supports nearest neighbor, bilinear, and cubic
  resampling
• Supports output pixel size specification

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Accomplishments (cont.)

• Resampler supports scripting with various
  command-line options
• Logs output to log file
• Runs on all target platforms (Windows, Linux, Sun
  and SGI)
• GUI (originally Tcl/Tk, now Java) runs on all
  target platforms

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HDF-EOS Issues

• Well-designed file format for MODIS data, much
  functionality in library routines
• Documentation not always clear and accurate, fair
  amount of trial-and-error
• HDF-EOS vs. HDF issues
• Metadata
• Background fill values, valid range, etc.

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To Do

• ISIN-specific resampling calculations
• Support for swath data (Level-1/Level-2)
• Support for 3-D and 4-D data sets
• Testing
• Documentation

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Testing

• Testing challenge
• 9 projections
• 8 data types
• 4 platforms
• 2 input file formats
• 3 output file formats
• 3 resampling types
• spectral subsetting (36 Level-1 bands alone)
• spatial subsetting

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Future enhancements

• Efficiency improvements process selected bands
  in parallel
• Concurrent/distributed processing
• Remote processing
• Incorporate HDF-EOS viewer, allowing graphical
  subsetting
• Generalize MODIS Tool to process other data
  formats and map projections