The constellation tasking system continually rebalances the new acquisition schedule in a manner that maximizes utilization of constellation imaging capacity while honoring the acquisition window timeframe and collection tier constraints of all requests. Capella reserves the right to adjust the timing of tasking requests as long as the movement is within the user requested acquisition window duration. In other words, tasking requests may be automatically rescheduled by the Capella system within the scope of the requested collection acquisition window. For example, if a user has submitted a tasking request an 8 day collection acquisition window, Capella may move the time of imaging anywhere within that 8 day window.
Tasking Request Importance for the Scheduler
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. Capella’s collection tiers indicate for the importance of an individual tasking request for the scheduling system.
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. Repeat requests submitted with the Routine tier are evaluated for scheduling before any other requests, including Urgent requests, to ensure a regular collection cadence is met.
Single, area, and repeat 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.
Tasking requests processed within the same scheduler run are evaluated with a heuristic that maximizes utilization of constellation imaging capacity given the collection tiers and collect constraints of requests while giving a secondary preference to new acquisition requests that were submitted to the queue at an earlier date.
Leveraging the Collection Tiers
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. Submitting tasking requests with a variety of collection tiers helps the scheduler discern the importance of an individual request within the larger deck.
If an Urgent tier request is submitted for the same time as a competing Priority tier request, the Urgent tier request will be scheduled while Priority tier request will be either schedule for a later date within the collection acquisition window or, if no additional imaging capacity is available, rejected.
However, if the Urgent tier request is placed after the Priority tier request has already been accepted and there is no available imaging capacity in the region within the collection acquisition window, the Priority tier request will not be removed from the schedule to accommodate the Urgent tier request. Users can use the conflicting tasks information for the rejected Urgent tier request returned with the rejection message to cancel the conflicting Priority tier request, if the task was submitted by their organization, and resubmit the Urgent task for scheduling consideration.
Acquisition Collection Window
Users are required to submit a window open and window close for each tasking request, which sets the timeframe during which the image can be collected. This window does not include the time from collection to delivery to the end user.
Another mechanism to help denote importance of an individual tasking request within a deck is setting the Window Close to a longer period. This is useful for instances where a user considers the tasking request to be of high 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 acquisition window is especially important for area tasking as this increases the changes of acceptance and completion. An area tasking request submitted with a Priority 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.
For example, a user can submit a tasking request with the following configuration:
- Window Open: 1/01/2021
- Collection Tier: Priority
- Window Close: 1/30/2021
- Window Duration: 30 days
In this case, once the tasking request enters the scheduling window, it will be repeatedly processed by the scheduler every 15 minutes. The tasking request will sit in the schedule queue as Active and be processed every 15 minutes until acquisition window has ended. At that point, request will be definitively set to a final status of Completed (entire AOI has been collected, Accepted (entire AOI can be collected), Expired (only a subset of AOI can be collected), or Rejected (none of the AOI can be collected).
Scheduling Process and Timing
The system processes new requests asynchronously as they are received to ensure requests are ready to be considered for scheduling during the next scheduler run.
There is a 15-minute timeout on each processing job. If processing does not complete within the 15-minute limit, the request will be marked as Error. If this occurs, resubmit the request for reconsideration. Once the request has been processed, it will wait in the Review state and not be processed for scheduling until the user approves the cost or had submitted the request with Pre-Approval enabled. Once the tasking request has been approved, the task will move to the Submitted state.
The scheduler processes requests that have reached the Submitted status every 15 minutes. When the request reaches the Submitted state, it will wait until the next new scheduling task starts before it is evaluated. It may also take up to 15 minutes for the scheduling process to run, which means it may take up to 15 minutes for a tasking request to move from the Submitted status to an Accepted, Active, or Rejected status.
The current scheduling window is a rolling today + 7 day horizon. A new tasking request will only be evaluated for scheduling if the window open time of the tasking request falls within the next 7 days. If the window open time of the tasking request falls beyond the current scheduling window, then the task will remain in the Submitted state until window open of the request falls within the scheduling horizon. Once the window open is within the scheduling horizon, the task will move to Active.
If the period between the tasking request window open time and window close time is longer than the scheduling window, the tasking request will remain in the Active status to indicate that the entire tasking request cannot be fulfilled within the current planning window, but may be fulfilled within subsequent planning windows. This is the standard workflow for area and repeat tasking. The status of the request will move from Active to Accepted when all imaging has been completed or the planned collects all fall within the current scheduling window.
Time Between Tasking Request Submission and Window Open
There are currently no limitations on how far in advance you can place your tasking request. A new acquisition tasking request can be submitted to the scheduler queue any time prior to the user's desired window open start time and will be evaluated once the rolling one-week-out scheduling window horizon is reached.