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The Scheduler


The OpenTel scheduler can generate schedules for continuous longterm observations within a global network of telescopes. Longterm observations refers to observations periods exceeding the lenght of one night, which is typically on the order of a few hours. The scheduler overcomes this natural limitation by scheduling a target with another telescope which can continue the observation. This way it is possible to perform observations of arbitrary duration.
In a network of many telescope different telescopes could be chosen to in a schedule. Therefore an additional criterion is necessary, to make a selection. The criterion employed here is optimizes for to the observation hight by the scheduling algorithm.

Usage

The scheduler is part of the ot-tools (located in the bin folder) and is called ot-schedule.
The help page explains its invocation.

photon:~$ ot-scheduler 
Usage:  ot-schedule [OPTIONS] TELLIST.txt TARGET.rtml
Generate a schedule for sequential observations in a telescope network.
    -h, --help                        show this info
    -d, --duration 24                 overwrite duration [h] of observation
    -s, --start 2008-09-01T12:00:00   overwrite start time of observation

The two input files are obligatory
  • TARGET.rtml - the RTML description of an observation
  • TELLIST.txt - a list of telescopes, either created manually or obtained from the broker
The target and the individual telescope coordinates are automatically extracted from the corresponding RTML files provided with the OpenTel package. The same is true for the observation time, but this can also be overwritten with command line arguments.

The following example documents the usage.

photon:~$ TARGET=Gl586A
photon:~$ START=2008-11-01T02:40:00
photon:~$ ot-scheduler -s $START TELLIST.txt $TARGET.rtml
Created `Gl586A.sch'
Amadeus.aip.de 2008-11-01T02:30:00 2008-11-01T06:50:00
FaulkesTelescopeNorth.faulkes-telescope.com 2008-11-01T06:40:00 2008-11-01T10:20:00
FaulkesTelescopeSouth.faulkes-telescope.com 2008-11-01T10:10:00 2008-11-01T17:50:00
RoboTel.aip.de 2008-11-01T17:40:00 2008-11-01T19:50:00
STELLA-I.aip.de 2008-11-01T19:40:00 2008-11-02T02:40:00

The first line defines the target name of the RTML target.
The second line defines the START time.
The third line executes the scheduler with the telescope list and target information.

As a result the the new schedule is displayed and two files will be produced

  • Gl586A.sch - ASCII file containing schedule
  • Gl586A.dat - a data file for plotting the schedule
The schedule consists the begin and end times of the observations at the corresponding telescopes.
The schedule file can now be used as an input for the ot-submit tool to submit the observation to the corresponding telescopes.

Plotting a schedule

The ot-plot tool can be used to produce a PS/EPS file of the schedule and to visualize the result.

photon:~$ ot-plot $TARGET.dat
photon:~$ gv $TARGET.eps




Schedule and corresponding altitudes during a 24 h observation of Gl586A as generated by the scheduler for a the given list of telescopes.