HDF-EOS Workshop IV September 19, 2000

MODIS Reprojection Toolpresented by

John M. Weiss, Ph.D.

Department of Mathematics and Computer Science

South Dakota School of Mines and Technology

IntroductionMODIS instrument launched recentlyMODIS 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)

Functional Requirements Ingest data in ISIN projection from HDF-EOS or

multi-file (raw binary) formatsTransform data to nine standard projectionsAllow spectral and spatial subsettingAllow three resampling optionsProduce data products in HDF-EOS, GeoTIFF,

or multi-file formatsExecution via user-friendly GUI or command

lineSupport for UNIX and Windows platforms

Major Software ComponentsGUI (Tcl/Tk or Java)ResamplerGCTP (modified to support ISIN projection)GeoLibHDF-EOS and HDF librariesGeoTIFF and TIFF librariesMulti-file I/O CodeParameter File I/O Code

Modules and Data

GUI

InputMetadata

File

ParameterFile

InputDataFile

UserInput

File InputLibraries:HDF-EOSMulti-file

Resampler

GeoLib

GCTPwith ISIN

OutputDataFile

OutputMetadata

File

File OutputLibraries:HDF-EOSGeoTiff

Multi-file

Accomplishments

Resampler processes 2-D gridded MODIS data products (Level-3)

Handles multi-file, HDF-EOS, and GeoTiff file formats

Supports all required map projectionsSupports nearest neighbor, bilinear,

and cubic resamplingSupports output pixel size

specification

Accomplishments (cont.)

Resampler supports scripting with various command-line options

Logs output to log fileRuns on all target platforms

(Windows, Linux, Sun and SGI)GUI (originally Tcl/Tk, now Java) runs

on all target platforms

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.

To Do

ISIN-specific resampling calculationsSupport for swath data

(Level-1/Level-2)Support for 3-D and 4-D data setsTestingDocumentation

TestingTesting 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

Future enhancements

Efficiency improvements: process selected bands in parallel

Concurrent/distributed processingRemote processingIncorporate HDF-EOS viewer, allowing

graphical subsettingGeneralize MODIS Tool to process other

data formats and map projections