Published on February 21, 2014
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 email@example.com 1
Genesis – ESDIS Prototype HDF_EOS IV 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 2
Realize the promise of HDFEOS HDF_EOS IV One tool to open, read, display and subset any data set Utilize geolocation metadata Provide simple interface for geographic subsetting, subsampling, and export 3
DAAC Perspective Be able to provide a single tool for all polar gridded DAAC data sets • • HDF_EOS IV Heritage: AVHRR, SSM/I, TOVS Future: MODIS, AMSR, GLAS 4
Demonstration The Polar HDF-EOS Data Imaging and Subsetting Tool • For any HDF-EOS file a user can: • • • • HDF_EOS IV IDL-based (multi-platform) 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 5
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.
User first selects one or more files to open. Metadata is read and displayed. User then selects field(s) to load. Table of values includes location and size of selected region. Double clicking in a box brings up this menu. (Print and Write to File Selecting “View will be added.) Image Data” brings up window from which user selects field to visualize. Top level window is scaled to fit user’s display while showing entire data array. User can load multiple fields and toggle Instructions for defining between them or display them a in newregion of interest (ROI) in windows. any visualization window. Box parameters displayed while user positions box. Multiple ROI boxes can be registered. Contents visualized in new window and can be displayed in a table.
Image with Legend Includes palette and a thumbnail image locating the current window in overall array if zoomed.
New Features to be Added HDF_EOS IV 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. 12
Conclusions HDF-EOS enables discipline-specific tools to be developed Polar HDF-EOS Website created • HDF_EOS IV http://nsidc.org/PROJECTS/HDFEOS 13