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For N fields there is an N x N symmetrical matrix that lists the time overhead required to move the telescope from field i to field j. These times depend only on the angular separation between two fields, and the matrix only needs to be computed once.
The temporal observing inefficiency factor is the additional overhead imposed by slewing, after accounting for focal plane readout. A candidate observing sequence should have its overall merit score adjusted by a slewing factor that is given by SF=(t_slew/t_total), where t_total is the total observing time available.
Filter Exchange Overhead Matrix
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- determine the rank-ordered priority of all fields on the meridian, in each passband, for different potential values of seeing.
- reject the fields that never appear in the top 1000. These have such low priority we'd never get to them.
- For each parametric value of seeing, compute the sequence of observations that maximizes the merit function, including the slew overhead contribution.
A merit function
Some references
LSST science book
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