What are Capella's Collection Tiers?

The constellation tasking system supports a variety of tasking types – Repeat, Single, and Area -- with dedicated collection tiers to give the user control over the cadence and collection importance of the tasking request. Single tasking requests are for one-time collections over a point target while area tasking requests are for a polygon location requiring multiple, one-time collections to cover the entire AOI. Repeat tasking ensures regular collections over a point target at a user-defined cadence and can also be used to ensure geometrically similar collections over time. 

When a new acquisition tasking request of any type is submitted, the user is required to select a Window Open and a Collection Tier. The Window Open denotes the first possible date and time the collection should be acquired while collection tiers are used to denote tasking request importance for the scheduler. 

Single and Area Tasking

• Submit a tasking request for an acquisition at the next possible collection opportunity
• Target a precise imaging geometry or a specific data window within the scheduling horizon
• Differentiate the importance of individual tasking requests within a customer's submissions

A tasking request submitted at the Priority tier takes greater importance for the scheduler than a Standard task while tasks submitted at the Urgent tier take the highest importance.

These types of tasking requests can also be submitted at the Flexible tier, which is geared towards opportunistic collection and does not come with “No Bumping” assurance. It is possible that a Flexible task will get added to the schedule and more frequently shuffled, or fully removed, if a tasking request with higher importance needs the imaging slot.

Submitting tasking requests with a variety of collection tiers helps the scheduler discern the importance of an individual request within the larger deck. It is critical to leverage the full range of collection tiers when submitting a large tasking deck as a single batch. Submitting all tasking requests from a deck with the same tier instructs the scheduler to optimize the total number of tasking requests accepted, regardless of submission order. 

Another mechanism to help denote importance of an individual tasking request within a deck is setting the Window Close to a period longer than the minimum acquisition window set by the chosen Collection Tier. This is useful for instances where a user considers the tasking request to be of higher importance but would accept data collected outside the default acquisition window or where the user would like to receive very precise imaging geometries. Extending the acquisition window helps the scheduler consider more collection opportunities for an individual tasking request while emphasizing collection importance of the task for the scheduler. 

Extending the Window Close well beyond the default set by the chosen collection tier is especially important for area tasking as this increases the changes of acceptance and completion. An area tasking request submitted with a Priority collection tier and an acquisition window of 30 days will have a higher importance over a new single tasking request submitted with an Urgent tier as the scheduling horizon gets closer to the Window Close date in order to ensure imagery is collected over the entire polygon. 

Repeat Tasking

The Routine collection tier is exclusive to Repeat Tasking. Users should leverage this tier when a regular collection cadence and/or geometrically similar collects over time are a key requirement because Routine tasking requests receive the highest importance for the scheduler. Sub-tasks generated by a repeat request at the Routine tier are evaluated for scheduling before any other requests, including new tasking requests, when the Window Start Date for the sub-task enters the scheduling horizon. 

Repeat tasking requests can also be submitted with the Flexible collection tier. As with single tasking, requests created by repeat tasking at the Flexible tier do not have Capella’s “No Bumping” assurance. Any tasking request submitted with a collection tier of higher importance can bump a Flexible repeat request from the schedule, even if the task has moved to Accepted, should the capacity be required to fulfill the new, more important request. Users will not be notified that this is why the task has been removed from the schedule – only that the task has moved to Expired.

For more information on how Repeat collection tiers work and when each tier should be used, please see the Collection tiers for repeat tasking support article.