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What's New in OASIS

Version 2.9 (15 Aug 2004)

• Increased WCS Support. More WCS projections have been tested (specifically ZEA). Special code was added to handle odd behavior for WFPC2 (CTYPE1 and CTYPE2 are flipped). If images are rotated 180 degrees (North down), they are adjusted for easier viewing.
• Support for Distortion Parameters. Spitzer Space Telescope images have an additional set of distortion parameters in their header (e.g., CTYPE1 = "RA---TAN-SIP". These are meant to characterize corrections to focal plane coordinates before any WCS computations are made.
• Large Image Support. The FITS library we were using had some trouble with large image files. This has been corrected and tested up to ~200 GBytes (though there should now be no limit).
• Miscellaneous Color and Annotation Changes. Coordinate grid label positions near the poles have been improved; When drawing multiple catalogs the colors used are cycled (unless the user overrides them) for clarity; The location associated with a user label is marked with an 'X'; Polygon curves are draw right up to image boundaries (there was an occasional gap).

• Updated Window Management. Since Oasis is able to show a large amount of detailed information (tabular data, file downloads, etc. the screen can very rapidly get cluttered with unwanted windows. In this version, we have removed most of this by more carefully managing when data is displayed and by introducing tools for getting summary data without requiring the display of large numbers of tables (see below).
• Source Info Panel. When a user selects a location on the display, all nearby records in the associated tables are highlighted. Since we now no longer display these tables by default, we have introduced a new summary window where the user can browse through the collected records from all active tables in one compact place.
• Multi-part / Multi-plane FITS Files. If the input FITS image file contains multiple parts, Oasis brings up a window to allow user selection of the specific part to be displayed. Similarly, if the selected image is a data cube (or higher), this same interface allows specification of which plane to view.
• Image History. Oasis now maintains a history of images previously viewed and allows the user to jump back and forth between these views. The color table, stretch, and zoom parameters are remembered as well, so the display really does reset to the previous view (not just the previous image).
• JPEG Display Support. JPEG images can now be used as the base image for Oasis. Since JPEG contains no World Coordinate System information, we are currently carrying this along in a separate file (ASCII with FITS-header-like syntax).
• Updated JPEG Writer. The original Oasis JPEG writer used a simple screen-memory capture facility. This has been rewritten to more properly use internal memory management and also to output a header so these images can be used with the JPEG display functionality above.
• Updated File Selection. The file selection widget has been updated to include a file history.
• Updated Default Source Colors. When multiple source tables were displayed, Oasis originally set the initial symbol color to green. Now, it cycles through a color set.
• ZIP File Support. If a remote archive wishes to download a collection of data files (and optionally an associated organizational structure), this can now be done by simply ZIPping the data structure and sending this as the result. Oasis will display the ZIP structure and allow the user to pull out individual data files for display.
• Labels. Oasis now supports user labelling on the display.

Version 2.0 (1 Jun 2002)

• File Transfer Manager. Oasis now performs all data request processing through a centralized manager, which handles each request through a separate thread and provides a GUI for monitoring progress and controlling the process.
• Cache. In conjunction with the File Transfer Manager, Oasis maintains a temporary cache (.oasis in the user's home directory). Files not saved explicitly (a function of the File Transfer Manager) will be deleted automatically.
• Oasis Links. Mechanisms have been added to Oasis to make it simple for other data suppliers (and indivuals for their own use) to use Oasis (and each other) to create data visualizations and to fuse disparate datasets together in custom ways. See the Oasis home page for more detailed information.
• Third-Party Data Services. All of the IRSA data services and services from several other sources have been updated to make use of the Oasis Link functionality. This can be done without consulting IRSA, though we maintain a list of such services for information purposes.

  The NED, 2MASS image metadata, and ISO services which were originally special functions in Oasis are being phased over to this approach and no longer appear as custom buttons on the Oasis window. They and the others can be found on the Third-Party page (button "WWW", or from the Oasis home page).

• VizieR Update. The VizieR catalog search GUI has been updated to provide access to all VizieR catalogs. For those not on the pulldown, consult the VizieR documentation for ID value and enter it in by hand. The rest of the functionality remains the same.
• JPEG Output. The contents of the display (image and all overlays/annotation) can be saved at any time to a JPEG file of the user's choosing.
• FITS Header Display. The header of the FITS image (or headers for a multi-part file) can be displayed in a GUI window. This mechanism will eventually be used to control access to FITS extensions and to planes in data cubes.
• Coordinate History. A simple coordinate history mechanism has been created. At any time, a selected location can be added to the list and this "current location" can be used from various other windows (e.g. image archive and catalog searches). In addition, this list itself can be manipulated (in a simple GUI) and saved to disk.
• Sky Drawing XML. We have defined a simple XML syntax for drawing curves (e.g. contour maps) on the sky. Each opened/downloaded SkyDrawing XML file will be added to the display as a separate layer. See the User's Guide for format information).
• Sky Drawing Tables. A variant of our normal ASCII data tables can now be used to charaterize simple shapes on the sky (rectangles, circles, ellipses). Columns must be identified containing the shape type (one of the three above), size and rotation information. See the User's Guide for format information).
• Image Metadata Tables. Another variant of our normal ASCII data tables can be used to hold image metadata information which will be used to draw outline boxes as another layer on the display. Columns in the table must contain the basic FITS header geometric information (CRVAL1, CTYPE1, CDELT1, etc.). See the User's Guide for format information).
• XY Plotting. Downloaded (or loaded) data files can contain plot data (XML; see the User's Guide for format information). Such files will be rendered in a plot display which allows simple control of zoom/pan, colors, etc. and some interaction with the data. This mechanism is used by such IRSA services as the SWAS spectrum plotter and the AAVSO variable star light curve plotter.
• Data Collections. IRSA has begun a major initiative to instantiate a model for data collections. Oasis currently contains some simple examples of this: a set of data files can be returned as a set (ZIP file), complete with simple display directives information. This rudimentary mechanism was implemented as a prototype is currently being used to download ISO coverage metadata.
• Parameterized Shape Display. Data tables can now specify shape information (ellipses, boxes, circles). The table header must contain enough information to define the columns containing this information.