1 The Polar HDF-EOS Data Imaging and Subsetting (PHDIS) Tool Siri Jodha Singh Khalsa Emergent Information Technologies, Inc. National Snow and Ice Data Center, University of Colorado

HDF_EOS IV Genesis – ESDIS Prototype  Evaluate suitability of HDF-EOS for data sets in polar projections  Convert sample NSIDC DAAC data sets to HDF-EOS  Build tools to subset, subsample, visualize and export data fields from multiple products

HDF_EOS IV Realize the promise of HDF-EOS  One tool to open, read, display and subset any data set  Utilize geolocation metadata  Provide simple interface for geographic subsetting, subsampling, and export

HDF_EOS IV DAAC Perspective  Be able to provide a single tool for all polar gridded DAAC data sets Heritage: AVHRR, SSM/I, TOVS Future: MODIS, AMSR, GLAS

HDF_EOS IV Demonstration  The Polar HDF-EOS Data Imaging and Subsetting Tool IDL-based (multi-platform)  For any HDF-EOS file a user can: examine data contents visualize and compare the data fields overlay lat/lon lines and/or coastlines designate subregions for zooming in on or displaying values

Opening Window  Select one or more file to examine  When one or more files have been selected the Load Data Field(s) window is opened.  When data fields have been loaded, user returns to this screen to View Image Data

Selecting Data to Load  Available fields from all selected files are displayed along with projection information.  Clicking on a field name loads it.

Displaying a Data Field  Selected fields are grouped by projection.  Clicking on a row will open a window containing the first field in that projection.  User may replicate the window or toggle through the images in the default window

Initial Display  Data displayed with gray scale palette.  Mode menu changes click action Toggle images Define zoom box Browse: select between multiple zoom boxes.

Metadata is read and displayed. User then selects field(s) to load. User first selects one or more files to open. Top level window is scaled to fit user’s display while showing entire data array. User can load multiple fields and toggle between them or display them in new windows. Multiple ROI boxes can be registered. Contents visualized in new window and can be displayed in a table. Instructions for defining a region of interest (ROI) in any visualization window. Box parameters displayed while user positions box. Table of values includes location and size of selected region. Selecting “View Image Data” brings up window from which user selects field to visualize. Double clicking in a box brings up this menu. (Print and Write to File will be added.)

Image with Legend  Includes palette and a thumbnail image locating the current window in overall array if zoomed.

HDF_EOS IV New Features to be Added  Coupled images from different grids.  Coastline and graticule overlay in zoom window.  Autoreplicate for 3 or less fields.  View Core and Structural metadata.  Mapping between table cell and image pixel  Read and display swath data.

HDF_EOS IV Conclusions  HDF-EOS enables discipline-specific tools to be developed  Polar HDF-EOS Website created