Data Processing

A few simple data processing tasks are best performed inside the Oasis environment. This includes such things as subsetting data tables based on regions on the sky and some image filtering. At this time, the only such tool included in the Oasis release is a contour map generator. You may also utilize the coordinate history, or image history.

Contour Map Generator

The currently displayed image can be use to generate a sky drawing file containing image contours. When contouring is selected, a control panel appears with an editable list of default contour levels (in image flux units). These levels are chosen based on the image range stretch defined by the user, so the best idea is to select a color table such as the one labeled "thermal", adjust the data range and transformation until the image looks good, then fire up the contouring.

The contours generated are placed in an XML file of the users choosing and contain move/draw directives on the sky. They can therefore be retained as the user moves from image to image and will be drawn correctly independent of changes of scale and projection.

To aid in understanding the contours, they can be color coded automatically or can be set to a single specific color.

Coordinate History

Oasis provides a straightforward mechanism for maintaining a coordinate history. The user can save the "current location" (the last point selected on the image or in a table) to a memory list, use this last-saved location in a variety of places (archive search GUIs, on third-party Web forms), or view/edit the complete history and save it to disk.

To save a location, select it on the image and press the "Save" button in the lower right corner of the main Oasis window. This information can be managed through a window brought up under "Tools / Show saved coordinates"

Image History

As images are displayed, Oasis keeps a history of all the presentation parameters associated with each one (color table, zoom, etc.). The image history window allows the user to jump back and forth between these views, providing a quick and easy mechanism for intercomparing images.