查看AZ-GTI的源代码

== 调试记录 ==

[https://www.cloudynights.com/topic/658474-skywatcher-synscanaz-gti-alignment-instructions/ Syncscan GTI alignment instructions ]

赤经以天子午圈（太阳正午）为 0 点，顺时针为正，逆时针为负，即上午为负，下午为正。数值等于离正午的时间（小时）乘以 15度


Connect Synscan in AZ Mode（经纬仪模式）:
*  The Axis coordinates are set to (0, 0), which represents North/Level.
*  This North/Level position has the power button pointing west, and the saddle is horizontal... assuming a normal vixen rail mounted scope


Connect Synscan in EQ Mode（赤道仪模式）:
* The Axis coordinates are set to (-90, 90), which represents Polar Alignment position, or EQ Home position
* -90 means you have turned the mount so that the power button is facing north  (recall that 0 has the power button facing west in AZ mode)
*  90 means you have the saddle turned vertically, upwards, pointing at the zenith  (your saddle is now on the south side of the mount)，鸠尾槽垂直于地面，延长线直指当前纬度的中天
*  Using the Altitude adjustment knob on your wedge will tilt the scope northward from zenith towards Polaris, stopping at your latitude (or 90-yourlatitude depending on your wedge marks) pointing at Polaris. 从当前纬度的中天，朝北旋转 （90 - 所在地纬度）即可将鸠尾槽延长线粗略与地轴平行，大致指向北极星
*  The power button is now facing the ground at your latitude angle, with scope "on top" pointing at Polaris.

This is "'''EQ Home'''" position, pointing at/near Polaris.  I just eyeball down the length, off the tip of my scope at Polaris  (this is just to get the East/West close, since I already have my latitude/altitude dialed in on the wedge)


1. Setup your "EQ Home" position,

2. Turn the mount on and connect Synscan in EQ Mode, which sets the Axis to (-90, 90) effectively "synchronizing" or "agreeing" with your actual scope position.


If you've eyeballed your East/West so your scope is near Polaris, then your wedge knobs should have plenty of range.

At this point you proceed with the Polar Alignment routine of your choice...  if using Synscan, then it consists of:

* Star Alignment (gives Synscan a pointing model baseline so it can calculate PA and Level errors)
** Star Alignment needs to be one of the 2-Star varieties (or 3-Star), in order for Polar Alignment to become available in the Advanced menu.
* Polar Alignment  (will ask you to choose a star from the list  which is a nice feature not requiring a good view to the North/South)
** The mount will slew to that star, asking you to center with Synscan.  Confirming center will calculate PA and Level errors based on the previous Star Alignment model baseline.
** Synscan will move the mount slightly, and ask you to re-center the star using wedge latitude knob only (You might not be able to get exact center, just get this axis as close as you can)

* Reset Alignment
** At this point you are Polar Aligned, only your Star Alignment has had the "rug pulled out from under it" because you moved your wedge knobs... so you need to Reset Alignment, and do another Star Alignment, in order to establish a new, accurate Sky Model.
* Star Alignment.


Theoretically, you could at this point check your Polar Alignment using another method, or doing another iteration of Synscan Polar Alignment/Reset Alignment/Star Alignment.

The several times I tested Synscan Polar Alignment i found it accurate enough for my imaging purposes with just the one iteration.

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