Changing observing mode

(Claudia Maria Raiteri) #1

If saturation of specific objects is recognized after the first visit to a certain field (see Identifying Suddenly Saturated Objects in the Prompt Pipeline), can the observing mode be modified for the second visit to avoid saturation, for instance by shortening the exposure time of one of the two snapshots or by taking star trial images?

(Peter Yoachim) #2

We don’t currently have any plans to modify observations based on feedback from the object alert stream. If a known object gets so bright that it saturates (and people care enough about it that they want a good magnitude), that’s probably what smaller follow-up telescopes are for.

(Melissa Graham) #3

@yoachim, if a white paper was going to request that an OpSim be created with this kind of effect built in, what would you need to simulate it? E.g., an approximate rate of how many second-visits should be shortened per night, the locations of these fields (i.e., likely Galactic), and a distribution of exposure times for the shortened second-visit?

(Lynne Jones) #4

That sounds about right. Perhaps the rate would need to be magnitude dependent? And the distribution of exposure times might be distribution of delta mags that are desired (in case of observing in a different filter or different seeing / skybrightness)?

It would be good to make sure that ‘special data processing’ part of such a white paper discussed how to set up such a filter on the alert stream, so as to trigger a change of observing strategy. It’s a good question whether or not this would be “additional observations”, in the case that the other science cases for galactic plane observing didn’t want shorter visits … I wonder if it would be sufficient to say that the second visit would be split into two shorter snaps (that together would have a combined standard visit time)?

(Peter Yoachim) #5

I’d almost say this is an experiment that you could do after the fact? Just go through an OpSim database and identify the visits you think would need to be modified. If you’re just adjusting the exposure time of snaps, not the total time, then it shouldn’t have an impact on the rest of the scheduling. Even if you are adding something like an extra 1-s exposure, as long as there aren’t too many in the night that should be an ignorable perturbation on the scheduling.