For all tasking requests, the Scheduler will match the request to a collection opportunity that falls within the select look angle range. The larger the range, the more collect opportunities are considered. If a collection opportunity is available to matches all the parameters of the tasking request, including the look angle range, then the tasking request will be Accepted by the Scheduler. The tasking request will remain in the Active status if the Window Open of the tasking request is beyond the Scheduler’s scheduling horizon.
Setting a look angle range
When configuring a tasking request, the look angle range is determined by the Product Category selected. If you would like to set the look angle range to specific values, you can do so by changing the Product Category of your tasking request to Custom.
Look angle ranges are set using the offNadirMin and offNadirMax parameters in the API. Console provides a slider for setting the minimum and maximum range under Optional Parameters.
Relaxing look angle ranges to accommodate spacecraft state updates
The ephemeris, also known as spacecraft state, data used by the Scheduler to determine available collection opportunities is continuously being updated and, in rare cases, a collection opportunity may change enough that its look angle pushes it outside of the range for the previously matched tasking request. In those instances, the Capella system will start a process whereby it relaxes the look angle range of the tasking request to see if collection opportunity could still be valid.
For example, let’s say you submit a custom tasking request with a window open 6 days from today and a look angle range of 20 to 40 degrees. The Scheduler could match it to a collection opportunity with a look angle of 39.8 degrees and, therefore, will move the tasking request to Accepted because your request is within the scheduling horizon.
Let’s say that two days later the ephemeris data is updated, and the collect opportunity now has a look angle of 40.1. This opportunity is no longer within your designated range.
To keep your tasking request Accepted (or, Active if outside the scheduling horizon) given new updated collection opportunities, your look angle range may be relaxed. Under this process, a collect opportunity of 40.1 could be considered a valid collection opportunity for your tasking request.
Capella applies this relaxed constraint because ephemeris data could update again, showing the collection opportunity has a look angle of 37.4 and the opportunity is back within your range. If we did not apply this relaxation, then your task could be moved to to Rejected and would not be rescheduled, even if the ephemeris data updated to be back within your non-relaxed range.