Contents - Index

Initialization

Initialization is the process of telling CCDAutoPilot about your equipment parameters and arrangement.  Successful initialization is essential for automated imaging.  Before initializing. settings are needed for the imaging system, the guider and the mount.

Contents
Imager Settings
Guider Settings
Mount Settings
Initialization
Unguided Initialization
Guided Initialization
Hints
When to Re-Initialize
Easy Initializing


Imager Settings



CCDAutoPilot needs to know the approximate unbinned image scale for your imaging system.  Enter the OTA Focal Length in mm and the Imaging Camera pixel size in microns and press enter.  The Unbinned image scale will automatically calculate.  You can also click on the up/down arrows at the side of the entry box to adjust the values.

If you wish to use a portion of your imaging sensor for all your imaging, CCDAutoPilot will maintain your desired sensor cropping for light frames and all calibration frames, including flats.  When the Sub-frame box is checked, the Get button will become active and you will be prompted through the steps to define your sub-frame.  That definition will be maintained in your system profile.

For most users, the Auto button should be checked.  With this checked, flat frame auto-exposure will take into account your camera's bias level when targeting your specified ADU level.  This does not mean it will do an automatic bias or dark subtract.  That should be done post-acquisition with a high quality master bias.


Guider Settings



First, select your Method of guiding.  If you are using Self-Guided or Off-Axis Guiding, enter only your guider's pixel size in microns and your guider's binning.  If you are using a guide scope, enter your guide scope's Focal Length in mm as well as the guider's pixel size in microns and your guider's binning.  Be sure to set the A/D bits/pixel appropriately for your guider.  If you are using a CMOS guider, the appropriate setting should most likely be 8.  For CCD guiders, the setting should be 16.  Consult your guide camera documentation.  If there is any doubt, take an over-exposed image of a star manually with your camera control program.  Measure the peak ADU.  If it is 255 or 355, then set the A/D bits/pixel to 8; if it is 65535 or so, set the A/d bits/pixel to 16.


Mount Settings



Enter your mount type, either Equatorial or Fork.  

Enter your mount's guide rate, represented as a fraction of sidereal tracking rate.  Here it is shown at 0.50 and would typically be referred to at .5x.  This is generally a characteristic of each mount and can be set with most mounts.  For best results, guide rate should be a fraction of the sidereal rate.  Choose whether to use a double slew to the target.  With some mounts, a second slew releases belt tension for improved guiding.  Checking Dec. Axis Release will perform a programmed series of declination axis motions to release any binding and may improve guiding.  Caution: Be sure to verify observatory clearances visually before engaging this option.  The scope could slew +/- 25 degrees in dec. away from the target.

Enter a setting time for your mount.  This is how long you want to allow the mount to settle after a slew.  Values can range from 3 sec. for high quality, modestly loaded mounts to 30 sec. for lower quality or more heavily loaded mounts.  You will need to experiment on what is best for your mount.  

You can set altitude limits for your mount, depending on your OTA and camera geometry and observatory walls.  Setting a Min. W Altitude limit will insure your mount stops tracking before that limit.  This is a nice fallback in case you miscalculate your run time.  If Min. Alt is set to 0, there will be no minimum altitude limit applied.   If this limit is exceeded during a target run, the light frame acquisition will cease for this target.  Either the next target will be selected and acquired or the next programmed task will be executed.  Max. E and Max W. Altitude limits can prevent your OTA from coming too close to your pier or tripod.




With the above setting, we are now ready to initialize CCDAutoPilot. You will need to be connected to your camera and telescope via the appropriate control programs and have selected a Plate Solve method.  If you are using PinPoint for plate solving, make sure the settings are correct on the Preferences page. For unguided imaging, CCDAutoPilot will confirm your image scale and determine the difference between your imaging camera and the Position Angle in TheSky.  If you are using a rotator, it will calibrate any rotator offset so that it can precisely move to a desired PA automatically.  For guided imaging, additional data will be taken on your guider's orientation and sensitivity by doing a guider calibration.  The necessary information from this process will be saved in the system profile.


Unguided Initialization

Simply point the telescope to a point in the sky above 60° altitude and hit the initialize button.  CCDAutoPilot will take an image and plate solve it.  You will given an opportunity to save the data to a system profile.  Please do.  


Guided Initialization

Point your telescope to a point in the sky above 60° altitude.  Adjust the telescope position so that a reasonably bright guide star is located in the guider's FOV.  With your camera control program, choose a guide star exposure to get a good signal.  Again using your camera control program, calibrate your guider, making sure the guide star stays on the guide chip throughout the calibration.  Once a successful calibration is completed, you are ready to Initialize.  Hit the Initialize button.  CCDAutoPilot will take an image and plate solve it.  It will then perform a guide calibration.  Upon successful completion, you will be given an opportunity to save the data to a system profile.  Please do.


Hints

Choose meaningful names for your profile.  Some examples are MX080526RY, which would mean to me Maxim, May 26, 2008, camera relays used.  Another might FSQCS0526DG, which would mean FSQ-106 telescope, CCDSoft, May 26, 2008, DirectGuide.  Anything that helps you identify the profile afterward.  Remember you can double click the profile to launch CCDAutoPilot so meaningful names are helpful.

As long as you don't disturb the relationship between your imager, guider and the sky, you don't need to initialize again.  No matter where in the sky you image, any RA, Dec or PA, either side of the meridian, CCDAutoPilot will provide optimized calibration vectors to your camera control program.  (These are not simple transformed guide vectors from a possibly marginal calibration; these are derived from proprietary algorithms to optimize guiding performance.)


When To Re-initialize
  • Imaging telescope FL change, either different telescope or focal reducer
  • Guide telescope FL change
  • Different imager or guider
  • If using a powered rotator, change to the relationship between the imaging camera and/or guiding camera to the rotator
  • Change in guide method, e.g. from self-guided to Off-axis guided
  • Change in guide control, e.g. from camera relays to DirectGuide or MicroGuide
  • Change in guider binning
  • Change in camera control program, e.g. from Maxim to CCDSoft
  • Lose your home setting with the RCOS PIR


    Easy Method for Initializing

    This method requires TheSky6 and saves you from hunting the telescope position to get a guide star centered in the guider FOV.  Read the sections on Unguided and Guided Initialization.
    1. Perform an unguided initialization.  Save the profile.
    2. Using the techniques outlined here, position TheSky's FOVI so that a suitable guide star is in the guider's FOV.
    3. Slew to the FOV_Center target with precision slew checked.  Once the process completes, you should have the guide star on the guide chip.
    4. Run a guider calibration with your camera control program to insure the guide star stays on the chip for all movements
    5. Set your guide method as desired and initialize again.