What's New in OASIS
Version 2.9 (15 Aug 2004)
Version 2.7 (10 Oct 2003)
- 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
- 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
- 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
- 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
- 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
- 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
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
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
- 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
- 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
- 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
- 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
- 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