We are thinking on modifying the objective functions in rts2 in order to optimize the scheduler for our particular scientific purposes. This will require adding some extra information to each target, which should be easily accessible to the main merit function routines.

In particular, our database is composed of nearby galaxies. Each target (galaxy) should contain the following information:

- Physical quantities, e.g. mass, star fomation, metallicity, etc…

- Observational quantities: the time of the last observation

The physical quantities are simply analogous to the other quantities already present, like the coordinates in the sky.

For the observational quantities we have the added difficulty of requiring the time of the last observation to be updated within a given plan, to avoid looking at the same galaxy many times during the night. This is, if a given galaxy is observed at the beginning of the night, any additional observation should take this into account. (Can this be fixed by setting Ticket.obs_num = 1?)

Moreover, the time of the last observation needs to be updated every night, which makes the problem more complicated.

Hence, our questions are:

1. What is the procedure to add new information to each target? We imagine that using Postgres will be necessary, what are the particular commands that would help us?

1. Where does rts2 talk to postgres? Where can we add new parameters to each target?

Please see new_target_type for details.

1. How can we modify the database from rts2, so that after observing a target its new time of last observation would be updated?

In earlier versions of RTS2, this was kept as an extrea field in the database. Now you can use getLastObsTime () call. This returns in seconds time from last observation. If observation was not performed, it returns one year. But this can be easily changed to return nan, so you can use as you wish.

Additionally, we would like to fix the exposure times for all the targets. What is the easiest way of doing this in rts2?