This document describes how to create a non-interruptible exposure sequence; see the training movie. To create exposure sequences in APT, you create a Sequence Non-Int container that holds these related exposures (in the same way there is a Visit container holding all exposures in a visit). For exposure sequences, this container holds the exposures that, for scientific reasons, need to occur without the interruption of an occultation or SAA passage. Note that when using the Text file for your proposal, you need to use the SEQ NON-INT special requirement to tie the exposures together.

Creating the Exposure Sequence Container

To create the Sequence Non-Int container, you need to have the correct context set in the tree editor. Select either the Visit container or an exposure in the visit. Under the New button, select New Sequence to get the container.

Populating the container

With the container created, either copy/drag an existing exposure into it, or create a new exposure (with the context set to the container, select the New Exposure option). The container will now have a key on the left, which you can open to show the exposure inside. Also note that the title of the container now has the exposure number of what it contains appended to it. The sequenced exposures can now be added to the container.

Creating and Populating the container in 1 step

If you have already defined the exposures you want in the Seqence Non-Int container, you can select the exposure in the APT Tree Editor, go to the Edit Menu, and select Group/New Sequence. This will place the exposures in a Sequence Non-Int container.

Looking at the results

With the visit(s) specified, run the Orbit Planner to examine the results. See the Orbit Planner help and movie for more information.

The Orbit Planner output shows that all exposures in the group do occur in one orbit, without any interruptions. The reason orbit 1 is not packed is that the Sequence Non-Int Group cannot be interrupted by an occultation, and since both exposures did not fit, orbit 1 was left unfilled.

Last modified: May 9, 2014.