Reviewing Files

Saved data may be loaded and reviewed when the Spectrograph Viewer is not actively connected to the WCCRO Spectrograph server. File / Load Data File brings up a dialog to load the file. Files are saved with a sps extension in a directory structure familiar to Radio-SkyPipe users where the files for specific dates go into their own directories.

Spectrograph data files can be quite large and so are loaded in small viewable chunks as a file could easily exceed the available memory of the computer. After a chunk is loaded a "Please wait drawing … " message is displayed in the status bar.

The Navigation Panel makes it easier to get around in the file. Open the Navigation Panel if it is not already visible with View / Chart Navigation.

One aspect that may need some explanation is the X-Scale Factor. The width of the viewing area is fixed at 600 pixels. If more than 600 scans need to be viewed at once then we must either show only every nth scan or we must average n scans and apply them to a single vertical pixel column on the chart. Which of these approaches we take is determined by our selection under Options / File Review. If Average Data is checked then the averaging approach is taken. The X-Scale Factor determines the number of scans skipped or averaged. Non-integer values are acceptable here because the program interpolates.

You may also advance or back up the view using the right and left arrow keys. Use shift and the arrow key for full screen movement.

Changing color options redraws the screen. In review mode, clicking the up/down color multiplier buttons does not apply the new color multiplier. You must put the cursor in the color text box and hit Enter.

You may see a spectrum analyzer type display for any given scan by right clicking on the scan and selecting Scope View This Sweep. This is the only time that Chart #2 is used in the review process.

You may also use a sweep in Chart #1 to set the color offset array. Use the right mouse click to select the scan desired.