Non-interactive observing with CIMA has for a long time been available with the use of CIMA command files. Contrary to normal command file observing which requires a command file with a set of commands to be executed sequentially, auto-observing will use a list of sources and a list of instructions on how to observe each of the sources. However, there will be no instructions on when and in which order to observe --- these things will be decided dynamically by the auto-observing routine depending on the current LST, which sources are currently available and which ones have already been observed. Auto-observations will be useful for projects that want to run in absentee without the hazzle of generating specific command files for each observing session. Although the new facility will be available for any observer to use, the type case for which auto-observing is being designed is 'gap-filler projects'.
Gap-filler projects would be projects intended to make use of gaps in the schedule, either short gaps that are difficult to fill with other than X111 RFI monitoring or gaps that become available due to no-shows or instrument malfunctions that prevent a scheduled project from running. Gap-filler projects should be able to make use of even short observing sessions (15-30 minutes), should not require any interaction with a PI and should not be complicated for the telescope operator to run. A typical gap-filler project would have sources spread out over a large LST-range. Projects with a lot of sources not requiring too complicated observations, like follow-ups to surveys, are good candidates for gap-filler observations. If two hours of otherwise unused telescope time could be turned into useful observations as gap-filler observations each week, the result would be a net gain of 100 telescope hours in a year.
Let's assume that we have four sources: 'Ape', 'Baboon', 'Chimpanzee' and 'Gorilla' that we want to observe 10 times each with 5-minute ON/OFFs at C-band. We also want to do three 3-minute ON/OFFs at L-band for the source 'Chimpanzee'. Furthermore, we want to give 'Baboon' and 'Chimpanzee' a higher priority since we believe that they are more promising sources. The sources have all been defined in the catalog file 'monkeys.cat' and the C-band set-up has been saved in the CIMA configuration file 'cband.conf' while the L-band configuration has been saved in 'lband.conf'. An auto-observe file may then look like:
# Example of auto-observe file CATALOG = monkeys.cat CONFDEFAULT = cband.conf OBSMODEDEFAULT = ONOFF secs=300 waitsecs=45 caltype=hcorcal calsecs=5 PRIORITIES = FINISH_STARTED ZA_MAX=15 SOURCE = Ape 2.0 10 0 SOURCE = Baboon 3.0 10 2 SOURCE = Chimpanzee 3.5 10 3 SOURCE = Chimpanzee 3.5 3 0 CONF = lband.conf OBSMODE = ONOFF secs=180 SOURCE = Gorilla 2.0 10 0 # End of fileThe first lines in the file should define the catalog file, a default configuration file and a default observing mode with parameters given in the same way as in command files. Then, for each source to observe, there should be a 'SOURCE' line with four parameters: the name of the source (as given in the catalog file), a priority, a specification of how many loops to perform and a counter of how many loops have been performed so far. The last value should be given as zero and will be updated by CIMA. If a source should be observed in a different way than what the defaults are specifying, You can specify another configuration file or another observing mode set-up with 'CONF' and/or 'OBSMODE'. A source that should be observed in different ways should have one specification for each way. Some general priorities can be specified with 'PRIORITIES'; in this case 'FINISH_STARTED' which instructs CIMA to give priority to observe sources that have already been observed instead of starting on new sources, and 'ZA_MAX=15' which specifies that observations should be done below 15 degrees zenith angle.
Note that You can must have one and only one 'CATALOG' specification and it must come before any SOURCE specification. The 'PRIORITIES' specification is optional, but again, only one is allowed. The 'CONFDEFAULT' and 'OBSMODEDEFAULT' specifications are also optional, provided that each source has explicit 'CONF' and 'OBSMODE' declarations. You can use multiple 'CONFDEFAULT' and 'OBSMODEDEFAULT' specifications --- any source that doesn't have an explicitly declared configuration or observing mode will use the last previously declared default.
Observers who are used with the command file observing should notice a difference in behavior: the default configurations are really behaving as true default settings should. The source 'Gorilla' will thus be observed with 300 seconds integration time as expected. In command files, any change to a parameter (like the change to 180 seconds integration time for the second 'Chimpanzee') becomes the new default.
It is also expected that CIMA will generate a special log with dates and times of when the different sources were observed.
You can return to the main CIMA page by clicking here.