How do you Schedule Observations?

Besides the observation planning tool, which lets you identify objects which meet given criteria, C2A also has a tool which allows you to generate observation schedules. This feature lets you add a number of objects to a list, and then order the list so as to optimise the observations you want to make on this list. The Observation Scheduling tool is accessible from the Telescope menu. MAJ+F9 is a shortcut for this command.

It is possible to add an object directly from a C2A map by right-clicking on this object and using the command Add to Schedule. It is also possible to add objects directly from the Scheduling Tool using the appropriate button. Objects can also be added from Observation Planning tool. Once objects have been added to the Observation Scheduler list, a certain number of actions can be undertaken. The screen shot below as well as the associated notes describe a typical usage of the tool:

  1. The first thing to do consists in sorting objects in the Scheduler list using the appropriate Up and Down buttons.
  2. Once the objects have been sorted, you must specify at which time the first observation in the list will be started.
  3. This time of first observation can be expressed in Universal Time or local time.
  4. You must also specify the default duration of each observation that will be used if a specific duration for a given observation has not been specified yet.
  5. If the option Overwrite is checked, the compution of the observation sequence will replace the existing durations with the value provided in step 4. In the opposite case, the existing observation duration for the items in the list will be preserved.
  6. You must then specify the duration between two consecutive observations.
  7. The next step consists in specifying the day of the first observation. This must be the day at which starts the observation night. This is an important point to keep in mind since you will not have to change the day after passing midnight during the observation session. C2A will automatically use the correct day during its computation. After being sorted, a Scheduler list will show first observations starting before midnight local time and others starting after midninght.
  8. Once all these parameter adjustments have been made, the computation is launched using the Compute button. During this computation, the order of the items in the list is not changed. Only the observation start times are adjusted.
  9. At any time it is possible to edit an itel in the list by double-clicking it or by using the appropriate button on the right of the list.
  10. Objects can be manually added to the list using this button. An edition window is displayed where you must specify as a minimum the name of the object and its right ascension and declination. Other information fields are optional.
  11. One or several items in the list can be removed using this button. Multiple selections are performed using the SHIFT key (continuous selection between two items) and CTRL key (items are selected individually) while clicking with the mouse left-button. Take care that object deletion is performed without confirmation. It is therefore advised to save the Schedule on a regular basis using the Save button (see point #19 below).
  12. This button lets you completely empty the observation schedule? A confirmation is requested from the user.
  13. This option lets you specify if you want to use the Universal Time or the local time in the Scheduler list.
  14. This option lets you specify if you want to display equatorial coordinates or horizontal coordinates in the Scheduler list.
  15. This option lets you specify that you want to display the observation tracks in the views of type Horizon. Take care that the observation tracks are not displayed in views with the Field type (this would be useless since the observation tracks are only used with respect to the horizon, i.e. is the observation below the horizon?, will it go through the meridian?, ...).
  16. This button lets you quickly display a global view of the horizon in the current view. An other way to do this would be to use the key "Z" in the main map (view with the Horizon type centred on zenith with the South at the bottom of the view).
  17. This button lets you refresh the Scheduler list and the tracks in the map when the date is changed (see point #7) or when the item characteristics have been changed (see point #9).
  18. Thi sbutton lets you sort the list of items in the Scheduler list by increasing observation time. As opposed to the schedule computation (see point #8), the times for the observation beginning are not adjusted but the list order is modified.
  19. These two buttons let you save and load observation schedules. It is important to save the observation schedules on a regular basis while building them.
  20. These two buttons let you print and export to a text format the current observation schedule.
  21. This button lets you center the view on the object selected in the list.
  22. This button lets you slew the telescope to the object selected in the list.

The screen shot below shows a global view of the horizon with the observation tracks in green that show what will be the path of the telescope during the observation session that has been developed. These tracks should not be analyzed with respect to the objects in the map (since every single point in these tracks correspond to a different time), but they should be analyzed with respect to the horizon. The tracks show what will be the position of the telescope in azimuth and altitude during the full observation session. The observation tracks are linked together with gray lines in order to better see the sequence of observation as established in the Scheduler list. The numbers near the observation tracks refer to the numbers in the list. Note that if two observations conflict in the list (i.e. one starts before the previous one is not complete), the gray lines are not displayed in the map.


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