First, you need to select a tool from the main CASPER widget, by clicking on Target, Skymap, 3DView, Batch, or Events.  In this manual, we will focus on the Target tool, with discussion of Batch and Events.  More detailed discussion of Skymap, 3DView, and Track are available in the MAPSGAP User's Guide.  Once you have selected a tool, whether with the Target, Skymap, or 3DView tools, you need to tell CASPER what time you would like to display in the tour.  This is done through the Session Data Entry Widget, accessed by the Clock button on the Target and Skymap tools, or by selecting "New Plot" under the file menu of each tool.  Using this widget, you specify a time of interest, a target body, and an observer (the spacecraft).  The time selected will be the starting time for any observation designs.  It is important to remember that SPICE kernel data must have been loaded for the time, target, and observer selected in order for CASPER to produce a plot.
The top of the window is where the data is entered. CASPER needs a start time, a target body, and an observer in order to construct a plot.

The Start Time text widget accepts a UTC time for the start of the plot in most standard UTC formats and will convert it to CASPER's internal UTC representation. (Do not forget to press the RETURN key to enter data into a text widget).

The target body is selected from the target body scroll list menu. The target highlighted displays the name of the currently selected target.

The observer is selected from the observer scroll list menu. The observer highlighted displays the name of the currently selected observer.

The last item in the data Entry panel is the Plot button that will use the entered data to create a graphics plot in the main CASPER window. The window is also iconized at this time.

In order for CASPER to create a plot, the Target body and Observer information must be loaded in the kernel pool for the time selected. If there is insufficient data, an error message will be displayed. Use the kernel viewer to verify the kernel bodies and time periods if you encounter this error.  An error will occur if insufficient data has been loaded from the SPICE kernel pool to plot the target body, from the observer, at the requested time.  If you get this error message it is probably because your tour kernel does not include the time specified, or there is a mismatch between the observer and the tour kernel.

Below the Data Entry Panel is the History buffer panel, which consists of the history file status, history buffer list, and control and action buttons. History files are saved in each user's casper_save directory. The first time you call up the Session Data Entry window, the list widget will be empty until you load a history file (see LOAD below) or ADD data from the Data Entry panel. The History File status text widget indicates the history file you are looking at, or indicates that no file is loaded. Items in the history buffer consist of a UTC time, a target body, an observer and an annotation that gives information about the item.
You may make the currently loaded history file local by default each time you run CASPER by selecting save default from the main CASPER widget Utilities menu.

Once you have some history data displayed, you can select a time/target/observer combination by simply selecting an item in the list widget. The data is copied into the Data Entry panel section and can be plotted by means of the PLOT button.

Finally there is a message text widget used to display information to the user.