NMSU 1m robotic observing procedure and syntax

The basic scheme is that a list of objects is constructed for each night. If the telescope is opened, it just works its way down the list. Starting with the first object, if the observing constraints are met (see below), the object will be observed. One of the parameters (see below) is the number of times to observe an object per night. Once this number of visits (which might be 1) is achieved, the object will be marked as done for the night, and will be skipped on subsequent passes through the list; the next object that meets the current observing constraints will be observed. Note that the order in the list is on order in priority, which is not necessarily the sequence in which objects will be observed; an object that isn't available until the end of the night can be put at the top of the list, which should guarantee that it will be observed once it becomes observable (so long as the telescope isn't in the middle of a long exposure sequence for an earlier target!).


Specifies a target name. This name will be used to construct files with a list of observations, so it cannot have spaces in it; if you give a name with spaces, they will be replaced with underscores. You can specify multiple targets with the same name, e.g. if you want to do several different exposure sequences on the same target.

Object coordinates

Specify object coordinates in either hh:mm:ss, dd:mm:ss, or decimal degree format. Equinox can also be specified.

Airmass constraint

Object must be at airmass greater than X(min) and less than X(max) for an exposure sequence to start. Once started, exposure sequence will run to completion, even if it goes outside the airmass limit (unless the telescope runs into a limit). If you have a long sequence and this will be a problem, use in conjunction with the hour angle limits (see below); this way you can start an object moderately low in the east, but not let it start low in the west.

UT constraint

UT must be between UT(min) and UT(max) for exposure sequence to start. Once started, exposure sequence will run to completion even if UT(max) is passed (unless the telescope runs into a limit). Also, note that there is overhead associated with slewing to a target, updating coordinates, focussing, and obtaining a guide star, so the actual exposures will not start for several (5-15) minutes after the object is chosen for observation.

Hour angle constraint

Hour angle of object must be between HA(min) and HA(max) for exposure sequence to start. Once started, exposure sequence will run to completion even if HA(max) is passed (unless the telescope runs into a limit). Negative HA is in the east, positive HA in the west.

Moon constraint

Object will be observed if moon phase is less than Moon Phase (max) OR distance between object and moon is greater than Moon dist (min) (or if moon is down). For example, if maximum moon phase is 0.5 and minimum moon distance is 60, the object will be observed if the Moon is less than half full OR if the moon is more than 60 degrees from the object (or if the moon is down).

Exposure sequence information

An exposure sequence is identified by an integer, which indexes into the exposure table; if many objects use the same exposure sequence, only a single one needs to be specified and it can be referred to by each object. For each exposure sequence, a specified number of exposures in a specified set of filters will be taken. All exposures in a given filter in a given sequence will be of the same exposure time; if you want multiple exposure times for the same target, define and specify multiple exposure sequences (i.e. repeat the target in a separate line with a different exposure sequence). If you wish to repeat the same sequence multiple times in a visit (e.g. cycle through a set of filters, then do that again), specify the number of sequences you want using Number of sequences per visit. If you wish to visit an object multiple times in a night, use the Number of visits to specify the total number of visits; if you specify -1 for this, the target will repeatedly be selected so long as the observing criteria (above) are met. If you want the repeat visits to have a cadence, you can specify a minimum amount of time (in hours) between visits. For example, if you specify a min time between visits of 2 for an object, the object will be observed, but not be repeated until 2 hours have passed (from the initial selection of the object). You can specify times longer than a night, e.g., givin a min time between visits of 36 will allow one observation every other night; of course, to guarantee that the object will be observed after the minimum time has passed will require that the object has priority over other objects that are accessible at that time.