Visit Planner
The Visit Planner performs a schedulability assessment of Pass Plans and Survey Steps.
Overview of Visit Planner
The Visit Planner analyzes the selected observations and shows dates when the observations may be scheduled (schedulability). The Visit Planner may be run on one or more selected Pass Plans, Survey Steps, or Execution Plans. Constraints checked by the Visit Planner include the general visibility of a target from the observatory as a function of time, and the impact of any constraints or Requirements.
Running the Visit Planner
In the APT hierarchical editor, select one or more Pass Plans or Survey Steps (or Execution Plans, if working on an approved program). Click the Visit Planner button in the top tool bar, then click the Update Display button (on the bottom of the Visit Planner form).
- The Update Display button is disabled after the Visit Planner has completed.
- Schedulability results are not saved with the program, but on the server. When the program is closed and re-opened you will need to click the Update Display button to retrieve the stored results.
- If any parameters that affect schedulability are changed, when you click the Update Display button the Visit Planner will compute new results.
- The Visit Planner may be run at any time by selecting Force Update Display from the Visit Planner menu.
Demonstration of the Visit Planner
Screen capture demonstrating the use of the Visit Planner. This graphic shows that Visit Planner needs to be run on the selected Survey Steps. The yellow caution symbols indicate the need to validate the selected Survey Steps by running the Visit Planner. Click the red Update Display button to run the Visit Planner.
The time for the Visit Planner to complete depends on the number of plans or steps selected and their complexity. Setting a shorter date range can reduce the time it takes for the Visit Planner to complete (see Set Processing Date Range).
When the Visit Planner run completes, APT shows either green checks 
or a red x 
indicating schedulablity. Click the plan or step to show detailed constraints.
Demonstration of Unschedulable Survey Steps
Screen capture of the Visit Planner showing an unschedulable Survey Step with diagnostics. To show detailed reports, click the small arrows to the left of each Survey Step. In this example, the red X on Survey Step 3 (in the tree editor) indicates that the step contains one or more constraints that cannot be met. In the timeline view, the red X on V3PA Range provides more detail, indicating Survey Step 3 is not schedulable with the given position angle special requirement.
Generally speaking, the less your survey steps are constrained by Requirements, the more likely that they will be schedulable without further interaction. Requirements that constrain scheduling are shown on the Visit Planner display:
- When all Pass Targets in all the Survey Steps are Fixed Targets, any special requirements are shown on each Survey Step.
- When any of the the Survey Steps includes a Region Target, any special requirements are shown on each Segment but not on the Survey Step (see the Figure of a Region Target in the Visit Planner).
Figure of a Region Target in the Visit Planner
Visit Planner showing schedulability when a Region Target is observed. In this example, Survey Step 9 observes a Region Target.
Notice the Visit Planner constraint "V3 PA OFFSET 10 FROM 9 by 167.0 +/- 5.0" (which was specified as the Linking Requirement V3 PA Offset 10 from 9 by 162 to 172 Degrees). The requirement was specified at the Survey Step level, but is displayed in the Visit Planner at the Segment level. Moreover, the windows for this constraint at the Segment level (which are only about two months long each) are not limiting the window at the Survey Step level (which is shown to be about three months long). This is because for Region Targets, the Survey Step level is showing the union of the schedulability of all the Segments.
Visit Planner Menu
When the Visit Planner is displayed, a Visit Planner menu is available on the APT menu. The Visit Planner menu has two options: Force Update Display, and Set Processing Date Range.
Force Update Display
Force Update Display causes the Visit Planner to run on the selected plans, even if the plans have not been updated since the last time the Visit Planner was run.
Set Processing Date Range
The Visit Planner calculates schedulability over a specified date range. The default date range depends on the program Category and Sub-Category:
- For categories GI (except for sub-category CR), COM, and NASA, the default date range begins 2 months before the start of the cycle, and ends 3 months after the end of the cycle.
- For all other categories (and for sub-category CR), the default date range is the full mission length (currently set to 28-Sep-2026 to 12-Dec-2031).
To set a different date range, select Set Processing Date Range from the Visit Planner menu. Dates are in yy.ddd format. Setting a shorter date range can reduce the time it takes for the Visit Planner to complete.
For additional questions not answered in this article, please contact the Roman Help Desk.