Extended Abstract (120K)10.4
NdEdit: A Tool for Browsing and Subsetting 4D netCDF Files
John R. Osborne, NOAA/PMEL/OAR, Seattle and OceanAtlas Software, Vashon Island, WA; and D. W. Denbo
NdEdit, a Java application, was developed to allow efficient browsing and selection of ocean data metadata. NdEdit can display metadata in up to 6 "cut panels" or views. Each view is a two-dimensional slice of a four-dimensional region (longitude, latitude, depth, time). All data in the collection perpendicular to the panel are projected onto a cut panel. Interactive "handles" around the perimeter of the cut panel are manipulated to change a filter region. Points outside the selected region are removed (filtered out) of the other cut panel displays. For example, a user can define a narrow filter band in the time dimension to reduce the number of data points shown in the longitude-latitude view. NdEdit also features coastline and bathymetry display in longitude-latitude view, user-settable horizontal and vertical axes, zooming, and delete or retain metadata in a selected region. NdEdit features a set of interactive tools for selecting data points in any of the cut panels including selection rectangle, polygon, and section line. NOAA-funded enhancements to Java OceanAtlas (a visualization tool for section-oriented profile data) are underway to allow inter-comparison of in situ ocean profile data with fields from numeric models and gridded in situ products (e.g. WODB). Comparing in situ data with gridded products requires the ability to extract "virtual" sections from gridded 4D data sets that match the spatial and temporal domain of the in situ data. A user must be able to quickly view the structure of gridded data and have access to tools for extracting subsets. The NdEdit user interface is an ideal paradigm for viewing the axis structure of gridded data files and it's existing selection tools can be used for defining subsets such as virtual sections. NdEdit will be enhanced to parse and display the grid structure of a gridded 4D data file. In addition, NdEdit will be extended to allow multiple cut panels of any particular two-dimensional slice (e.g., latitude-longitude) to accommodate the multiple grids typical of many models and include a facility for mapping the axes reported in the 4D file to NdEdit's standard axes (longitude, latitude, depth, time). Initially, enhanced NdEdit will work with files only in the netCDF file format that adhere to defined standards such as EPIC, COARDS, and Climate and Forecast Metadata Conventions (CF).
Session 10, Applications in Meteorology, Oceanography, Hydrology, and Climatology (ROOM 6B)
Wednesday, 14 January 2004, 8:30 AM-9:30 AM, Room 6B
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