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Sequence Tool

This tool is to control a sequence of exposure on one or more objects.
The current implementation support only sequential processing of the targets, a more sophisticated scheduler is planned for version 2.0,

The top grid show the current list of targets.

You can Load an existing file with a list of target, create a New one, Edit the current list, Copy to a new list or Delete a list.

Use the Start and Stop button to start or interrupt a sequence.
The Pause button allow to pause the sequence after the current exposure is completed.

The Status button show the detail of the current completion status of the sequence.

The Reset button remove all the completion status about the images already done, allowing to restart a sequence from the beginning.

When the sequence start it first check if the autoguider and camera cooling are available and try to start them if not. If the telescope is parked it will be unparked along with the dome if configured.

The Run unattended check box control how the program react in case of error.

  • If is not checked a message prompt you on the screen what you want to do.
  • If it is checked the operation is canceled. Also the termination actions are always taken anyway the sequence is stopped.

The bottom grid show you the plan for the current target.
When the sequence is running the current target and step is highlighted.


Sequence editor

After you click New or Edit, the target editor let you modify the list of target and the plan steps.


Target list

Add a target

A target can be an object you want to take the images, a script to run in the sequence, or a series of twilight flats. Click the corresponding button to add the target you want.
You can edit a value directly in the table or change the values for a whole column by a click in the column title.

Image an object

When you add an object, or click the Search button, the coordinates are searched in the internal database, if not found you can type the coordinates or click the Planetarium button to select the object in the connected planetarium application.
The coordinates can also be selected by plate solving the current image.
Or click the No move button to clear the coordinates and not change the telescope position.
Note that the target coordinates are always J2000 and could differ from those show by the mount or the planetarium if they use local apparent coordinates.

Select the exposure plan to apply to this target using the dropdown box, or type a new plan name to create a new empty plan. After a plan is selected you can change it's properties on the lower part of this screen. Use the Plan Save as.. button to make a copy of an existing plan.
The plan are saved in separated files and can be shared by many target list. This way you not have to edit the detail of the plan every time, so be sure to save the plan with a new name if the change you do is only for this target.

If you are imaging a fast moving asteroid or comet you can check the Update RA+Dec from planetarium column to ask the planetarium for the object coordinates just before the telescope is slewed to the target.
Be sure the planetarium is connected before to run the sequence.
Check the name of the object is compatible with the search function of the planetarium. No problem if you set the coordinate and name from the planetarium.
The planetarium must be set to follow the system time, otherwise the asteroid position is not updated.

Check Use astrometry to refine the position column to refine the telescope position with an astromery solved control exposure. This ensure the selected object is framed exactly as required.

You can check the Stay in place for autofocus column if you are sure the center of the image field contain suitable stars for auto-focus. It is recommended to use the Dynamic focus method in this case.
If unchecked, the telescope is first moved to a focus star of the magnitude defined in the auto-focus preference, and returned to the target after the operation.
The default value for this option is also set in the auto-focus preference.

Type the desired value in the PA column to move the rotator at the specified angle.
You can also use the current image orientation after plate solving.
Be sure the rotator is calibrated before to start the sequence if you use celestial PA.


Set the begin and end time

You can set a time range for this target to be imaged, it will wait for Begin time to start. If End time is reach during the exposure plan it is stopped and the next target is selected.
Select rise or set in the dropdown to automatically use the rise or set time of the object above the limits you define in the Observatory configuration, for the date of the observation. Similarly you can select a time from meridian crossing for the begin or end time.
To not use this function click the Any time button.

You can also select to not wait a target that not meet the begin/end condition. In this case it process the other targets instead of waiting. This can be useful if you have a list of target you repeat over the night using the option Repeat the whole sequence and take the object when they are visible, or at a given time from the meridian.

You can also select to skip a target if it is not fully dark night because of the twilight or because of the Moon. This way you can skip the faint target when the Moon is up and take them at the next repetition after the Moon is set.

You can also define when the whole sequence start and stop.
Check the box Start at“ or Stop at” and enter the time you want.
Check dusk or dawn to adjust the time for the astronomical twilight for the date of the observation.


Repeat a target

You can set this target to repeat it's whole plan for a number of time at a given interval between two consecutive start. Set the number of repetition in the target list.
To temporarily skip a target but keep it in the list you can set it's Repeat count to zero.

More option are available in the below pane if the count is greater that one. The interval is measured between two consecutive start of the sequence, this is not the delay to wait. If the interval is smaller than the total plan duration the next repetition start immediately.
You can also start a preview loop while waiting for the next repetition, this is useful to keep the Sun or Moon centered if you do an eclipse sequence.


Add a script

To add a script you just have to select the one you want from the list, or create a new script here.


Add an automatic twilight flat

To add an automated flat click the Sky flat button.
Note: to take a dome/panel flat set a standard No move target and use a plan with an image type = Flat.

Set if you want the flat series to be taken at dusk or at dawn, this change the position in the list.
Select the number of flat to take for each filter, the binning and finally check the filters to use.
The automatic exposure time must be configured in the flat preferences.
To better manage the changing sky luminosity the filter are selected from the darker to the lighter at dusk, from the lighter to the darker at dawn. This require you configure the filter exposure factor.
When you add a sky flat to the plan this disable the “Start at dusk” and “Stop at dawn” global options. Do not re-enable them otherwise the sequence will not run during the twilight and the flat are bypassed.
For the same reason you must be careful the sky flat remain in first or last position in the list. The only acceptable steps before or after them are script to manage the equipment because they will run in full daylight. The flat and this scripts are run only one time if the Repeat the whole sequence option is set.


Repeat the whole sequence

You can also repeat the whole list a number of time by checking the box at the top of the list. The Infinity button set a value of 999999.
There is no option for the interval here, the repetition is immediate. But you can add scripts in the sequence to delay the execution in a more flexible way.


Restarting a sequence

When running a long sequence you may find it not finish totally and you need to restart it to complete the missing frames. There can be a number of reason for that, maybe you just put too many frames to be taken in a single night, or you need to stop the sequence to fix something with the equipment.

To allow a sequence to be restarted at the point it was interrupted you need to activate the Keep completion status option. It is active by default for a new sequence but not for the one created by a previous version before this function exists to keep the compatibility.

The option Reset completion status on repeat define how Repeat the whole list manage the completion of individual targets.

  • If checked (default option), the targets already completed on the previous pass are re-done completely from the start. If the target plan define 5 images of M13 and the number of whole list repetition is 10 you end with 50 images of M13.
  • If unchecked, the target completion is not reset when the whole list is repeated. This meant that targets already completed are not done again. In the previous example you only get 5 images of M13. A typical use is a “Messier marathon”, you want 1 image of every Messier object taken when the elevation is high enough. For that you repeat the full Messier list of targets all the night and not redo the objects previously taken, only the new that are now high enough.

You can force a sequence to restart from the beginning by using the Reset button in the Sequence tool. Also beware that editing or copying a sequence partially done reset it's completion status.


Termination options

You can configure the action to take after the sequence is finished normally.

Select the actions you want from the list, for more action you can use a script.
In case of error an additional script can be configured for more actions. Click the ellipsis button to select the script, a question mask indicate that no script is configured.

This actions are not taken when you voluntarily stop a sequence with the Stop button and the Unattended checkbox is not checked.


Import a mosaic from the planetarium

You can import a mosaic definition from the HNSKY or Cartes du Ciel/Skychart planetarium. Be sure you connect to the planetarium before you start.

  • Take a preview image, plate solve and send the image frame to the planetarium. This ensure the planetarium know your exact CCD frame size and orientation.
  • Use the instruction from the planetarium software HNSKY or Skychart to create the mosaic.
  • Give a name to the mosaic frame, this will be the target name prefix in the sequence.
  • In the CCDciel sequence editor, from the “Insert rows” box, click the button “Planetarium”.
  • For HNSKY select from the right click menu “Export via server / All frames”.
  • For Skychart click the button “Send via server”. You can also save the mosaic to a file, then use the button “Import CdC mosaic”.
  • Close the planetarium import tool and adjust any option you want to take the images.

You can also use this import tool to input as many object you want from the planetarium, as long this tool is open any click in the planetarium insert a new row in the sequence.

Import observing list from Skychart

You can import an observing list from Cartes du Ciel / Skychart or other software that produce file in the same format.

Click the corresponding button to select the observing list you have saved from Skychart. All the objects from the list are imported with their coordinates.
The other option like the plan to use, the astrometry or the autofocus options are copied from the current target. If you import to an empty sequence, be sure to configure the default target so this is copied to the data you import, then remove this target after the import is completed.


Manage the target list

You can add a new target, script, flat or delete one with the four buttons at the bottom of the list.
The list can be sorted by name, RA or DEC by a click in the column header.
You can also change the target order with a mouse drag/drop on the first column of the list.

The target list is saved when you click the Save or Save as.. button at the bottom right of the window.


Plan steps list

Use the plan list to specify the exposure steps to take of a target.

Add a step

Give a description of the step that can be used to make a subfolder.

Set the type of frame, exposure time, binning, filter, number of exposure, gain, autofocus and dither as in the Capture tool.

Check corresponding box if you want to run an auto-focus at the start of this step.
For long steps you can also repeat the auto-focus after a given number of images or when the temperature change, as configured in the focus options.

The Gain column is only visible if supported by the camera and the option to use the gain from the driver is not checked.


Manage the steps

You can add a new step or remove one with the two button at the bottom of the list.

You can change the steps order with a mouse drag/drop on the first column of the list.

The plan is saved when you click the Save or Save as.. button.

If you no more need this plan you can delete it with the Delete plan button

en/documentation/sequence.txt · Last modified: 2019/12/02 16:34 by pch