This document describes how to create and use patterns; see the training movie. To create and use a pattern takes 2 steps. First, you create a pattern template, which will be applied to an exposure. Second, you create a Pattern container that holds the exposures to be executed at each pattern point. Note that when using the Text file for your proposal, you need to use the PATTERN special requirement to tie the exposures together.

Defining the template

To define the pattern template, set the context to the Pattern icon in the Tree editor. Next, click on the Select New Pattern Specification button, and select the pattern desired. Note that some patterns (e.g. LINE) allow sub-patterns to be selected (click in sub-pattern box), while most patterns have some items that are editable.

Using the template

Now that Pattern template is defined, it needs to be applied to an exposure(s). To create a Pattern container, set the context to either the Visit or an exposure in the visit. Click on the New Pattern button under the tool-bar, and a Pattern container will be created in the visit. Select the pattern template that is appropriate.

To place an exposure in the Pattern container, either click on the New/New Exposure button under the tool-bar (with the Pattern container in context), or drag an existing exposure into the container. At this point, you will note that the Pattern container has a key on the left, which when opened reveals the exposure. Also note that the title of the container has been modified to include the exposure number of the exposure(s) it contains.

Looking at the results

With the visit specified, run the Orbit Planner to examine the results; see separate documentation and movie on the Orbit Planner.

In this example, an 3-step pattern was selected. The instrument used was the WFC3/IR, which means that we get 2 exposures at each point in the pattern because we specify a number of iterations of 2. The pattern points are separated by pointing maneuvers.

If a second exposure at each pattern point is desired, a new exposure is added to the Pattern container. With the context set to Pattern 1-1 or Exposure 1 in the container, click on the New/New Exposure button. The diagnostics are due to the new exposure not being filled in, as well as the unassigned orbit numbers; see separate documentation and movie on orbit numbers.

Note that there are now 2 exposures executing at each pattern point.

If the first exposure was to complete its pattern, followed by a second exposure doing a complete pattern, then each exposure would be in its own Pattern container.

Note that exposure 1 now completes its pattern, then exposure 2 does the same.

Note that you can put coordinated parallel observations on the pattern points by inserting a Prime+Parallel group inside the Pattern container.

Last modified: May 13, 2014.