The purpose of the JCMT OT is to fully specify the observations you wish to be carried out at the telescope during flexible observing.
The JCMT OT enables users to build a science program for observing at the JCMT to execute both heterodyne and SCUBA-2 observations. A heterodyne template library and SCUBA-2 template library are provided which allow users to create MSBs for any available observing mode: Stares, Grids, Jiggles, Scans and Rasters for heterodyne, and PONG or DAISY scans for SCUBA-2.
In this document we will demonstrate how to prepare a typical observing project and point you to further sources of information as necessary.
Regular updates to our software means that investigators are urged to carefully inspect the examples provided in the Libraries. While the components will look familiar to experienced JCMT observers, most have changed, sometimes in a fairly subtle manner.
JCMT is a flexibly scheduled facility. But what is it that we are actually scheduling? The quantum of scheduling is a Minimum Schedulable Block, or MSB. An MSB consists of one or more scientifically meaningful observations as well as any calibrations required to fully reduce the data. An MSB will always be executed at the telescope in its entirety. MSBs naturally vary in length but it is recommended that a single MSB consists of a 30 minute to 70 minute observation on a single science target and any necessary calibrations. Note: SCUBA-2 observations should last no more than 40 minutes in length (see here for a longer discussion on this topic).
A library of MSBs for the most commonly used observing mode which are currently supported is provided. For a description of each, and help in creating your own program, please consult the following tutorials:
During flexible observing, the observer / telescope operator will run a tool called the JCMT QT (Query Tool) that allows them to browse our database for suitable project MSBs. The QT by default returns MSBs ranked by TAG priority containing targets that are actually observable, whose site quality requirements match the current conditions, and whose projects still have allocated time left. However, the observer / telescope operator is able to use the QT to retrieve any submitted MSB at their discretion.
When an MSB is selected for actual execution, the Query Tool can be used to retrieve it from our database. The MSB is sent via a translator which converts it into a complete set of configuration information for the telescope, receiver and backend. The observations are then placed in a queue for execution, where the observer / telescope operator are given the opportunity to remove redundant calibrations from the MSB or to defer them until a suitable calibrator becomes available. When they are satisfied that the MSB is suitable for execution they will start running the observations in the queue. As the queue works its way through the observations it can prompt the observer / telescope operator when intervention is needed before sending each observation to the control system.
After the observations have been carried out and deemed acceptable by the telescope operator, the MSB is marked as done and will not be rescheduled unless it is resubmitted from the JCMT OT or marked un-done via the project feedback system. If repeats of the MSB were requested (this is done by setting the Observe counter accordingly), the Observe counter is decremented by one and the MSB will continue to be rescheduled until the counter reaches zero.
There is no strict deadline for uploading programs / MSBs. However if you don't submit MSBs for your sources by the time they are observable you could be throwing away opportunities of having your sources observed. Nevertheless, note that there is no requirement that you submit your entire project at once. Therefore you can submit some MSBs, wait for them to get done so you can analyze the results and then submit other MSBs to follow up on those results. Your MSBs will keep on being scheduled until you have exceeded the total time allocated to your project.