Options to speed up calibration

Owned by Hendrik Beijeman
Last updated: Apr 19, 2020

Introduction

AutoGuiding means that you lock onto the stars, and try to keep them centered, even if they try to run away. To keep them centered, StarAid can steer the mount in the east, west, north, and south directions via the ST-4 compatible guide port on your mount.

However, before you can actually start AutoGuiding, you need to know for every direction what the orientation is. This orientation can be anything, depending on many factors, such as the way StarAid is rotated into the guide scope. But also meridian flips or mount configuration can alter this orientation.

Next to the orientation, you also need to know how fast the mount moves if it is steered in a certain direction.

To determine the orientation and speed of your mount means to calibrate it.

StarAid automatically calibrates your mount before it starts guiding. If you bumb into your setup, and StarAid loses a lock, or if you move your telescope to a new position, StarAid will (re-)calibrate your mount again.

Disabling automatic calibration

For some use cases, this automatic calibration is undesirable behavior. For example, if you take pictures of a certain object, and you want to check your camera between shots, it can be frustrating if StarAid starts to re-calibrate.

Therefore, since v1.5.3, an option is added to the Autoguiding page to disable automatic calibration. If disabled, StarAid will not re-calibrate your mount, but will simply resume guiding with the most recent calibration data, until you re-start guiding by hand.

Although you can calibrate only once during your imaging session, keep in mind that it may not be advantageous to do so, and in fact, you may get worse guiding:

  • The axes orientation changes slightly from different positions in the sky if you have a polar alignment error

  • The speed of correction of the RA axis depends on the declination. It is maximum on the celestial equator, but decreases to zero near celestial pole (except for alt-az mounts)

  • Meridian flips also flip the direction the north/south axes. However, the smart auto-guiding mode corrects for this automatically. The legacy modes do not.

  • The speed of corrections may change under different load conditions

  • The speed of correction may be changed by the user between imaging sessions, and you might forget to re-calibrate