Running Smart Accounting for JWST


APT tracks the science exposure time requested and produces an estimate of the total resources needed to execute a proposal by adding the appropriate overheads. Since the resources for each observation are calculated separately, there may be a tendency to overestimate the overheads a given proposal requires (e.g. observations that could be scheduled back-to-back with minor telescope slews needed are treated as separate observations with larger slew costs added). Thus, after ALL observations have been designed in APT, proposers need to run the Smart Accounting tool to remove any excess overhead charges and obtain a final resource estimate.

Step-by-Step Procedure

Below are step-by-step instructions for running Smart Accounting on your program. Our project is to mosaic the galaxy M51 using the MIRI Imaging template, and also obtain a spectrum of the nucleus using the NIRSpec Fixed Slit template.

If we look at the Proposal Information page, we can see that the charged time is 30.30 hours. Also note the warning symbol which reminds you to run Smart Accounting.

After you have input ALL your Observations, you will need to run Smart Accounting. There are 2 ways to do this:
  1. If you run all your observations through the Visit Planner (see the Running the Visit Planner with APT for JWST (document, movie) for more information) at one time (e.g. you select the Observations container), then Smart Accounting will be run as part of that processing.

  2. If you have run observations through the Visit Planner as you created them, you will need to run Smart Accounting manually. Return to the Visit Planner, and select Run Smart Accounting from the Visit Planner toolbar; alternately, you can run Smart Accounting from the Visit Planner menu.

    When processing is complete, return to the Proposal Information page and note that the Charged time has been reduced to 29.80 hours. Also see that the warning about needing to run Smart Accounting has been resolved.

Next, you can inspect details of Smart Accounting by getting a detailed look at what Smart Accounting did. Under the File Menu, select Export and then Smart Accounting visit sequences.

Examining the report shows that running the entire proposal through the Visit Planner and applying the Smart Accounting algorithm lead to a 1463 seconds reduction in slew time. But note that since the 16% Observatory Overheads is calculated on the time for the observation including slews, the final savings, which are shown as a reduction in Charged Time, is roughly 1463 * 1.16 = 2170s.

Last modified: November 22, 2017.