The task starts up by displaying a small progress-dialog box whilst it is doing some initialisation work. The image file is displayed using ds9. When the main window is displayed the user has a choice of actions, each of which is initiated by clicking the appropriate button.
If the user did not load an existing source-list file, the user will first have to either manually select sources from the image (by clicking the select sources button, or run the sas task omdetect (by clicking the omdetect button, to locate sources on the image.
In the former case the source-selection window is displayed and the user selects sources by clicking the left-mouse button. In the latter case, the omdetect is shown which allows the user to run omdetect on the image. For both cases, when finished, the main window is shown and the user can then proceed to either examine the parameters of a particular source, by selecting it, redo its photometry, or delete it.
When sources have been selected, by either means, or by using the optional parameter oldsrclistset, the region for each source is displayed on the image and the top list box is loaded with some parameters of each source.