APT Graphical Timeline

APT contains a graphical timeline tool to provide a high level insight to users on the detailed components comprising requested observations. 

See also: JWST Observing Overheads and Time Accounting OverviewAPT Smart Accounting

 APT Graphical Timeline Video Tutorial

When developing a proposal, APT uses a timing model and standard assumptions about overheads to report both the science time and the total time (including overheads) that will be needed to execute a given visit and observation.  

Running Smart Accounting at the end of your proposal development looks at the proposal in its entirety and adjusts the charged overheads to provide a total accounting of the resources needed for the program. However, just reporting a total roll-up of overhead time often leaves users wondering about the details, which are difficult to discern with the reports and information previously available.

Beginning with APT version 27.1, released in winter 2019, the JWST branch of APT now includes a graphical Timeline* tool that provides the user with a breakdown of the various overheads affecting their proposed observations.  Labeled color bars show the different components of the overheads in the context of each selected visit or observation.  Controls for zooming the display in the time dimension or providing additional details and labeling are available, as shown in the Figures below. Also, hovering the cursor over a color bar results in a pop-up window with additional information.

The graphical timeline is not meant to represent the actual detailed set of events that occur in the onboard execution of the observation. Rather, it is a tool to provide the user with insight into the major steps that occur and the times accounted for each step in the APT timing model. Furthermore, the graphical timeline does not capture indirect overhead charges, the most conspicuous of which is the observatory overhead charge that is amortized over all observations. The JWST Observing Overheads and TIme Accounting Overview article contains full details of overhead charges.

Figure 1. Example view of the APT graphical timeline

To access the APT graphical timeline: in the tree editor in the left sidebar, select an observation or visit. Then, select Timeline on the top tool bar (red oval #1). The Timeline tool will becomes active in the main GUI window as shown above. Use the Zoom (red oval #2) and the More Detail or Less Detail buttons (red oval #3) to adjust the display to your liking. Note that left and right mouse clicks can also activate actions. Hovering your cursor over a given color bar provides a pop-up with more information. This example uses a simple observation from APT demonstration proposal #6 titled "Mosaic Use Case Examples."
Figure 2. Accessing more detailed Information

This example shows a more complicated observation from APT demo proposal #7 (titled "MIRI Coronagraphy Example"), fully expanded to show detailed labels and additional colors. In this image, the full "Visit Slew" bar (olive bar at left) has been cut off to focus on details of the observational setup. Note that in addition to zooming in and showing More Detail, the slider bar (red oval) has been used to position the display on the region of interest.
Figure 3. A key to graphical timeline colors

Hovering your cursor over any of the colored bars in the graphical timeline displays more information on what it represents. Colors in the bar correspond to specific visit components, as shown above. These bars are also labeled in the timeline plot when you click on the More Detail button. Also, hovering the cursor momentarily over a color bar displays a pop-up window containing additional information.
* Bold italics style indicates words that are also parameters or buttons in software tools (like the APT and ETC). Similarly, a bold style represents menu items and panels.



Latest updates

  • Added clarification regarding absence of Observatory Overhead from the timeline plot.

    Added video link; minor updates.