Old 03-03-2024, 06:27 PM
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Mark_Heli (Mark)
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Join Date: Nov 2010
Location: Sydney
Posts: 153
Equatorial Mount Simulator

I have always found equatorial mounts and polar alignment difficult to visualise.

With some time over XMAS / NY, I thought I would try to create a simple simulator. I am not an expert in either eq mounts or simulators, so it was a good learning curve.

Features include:

* Accurate star positions from the Harvard Bright Star Catalog
* Ability to control lat, long, alt, az, ra & dec
* Go-To selected stars and back to home position
* Tracking
* Meridian Flips
* Indicator to show polar alignment accuracy

It was only intended for my use, but it has turned out quite well and maybe useful for others.

As mentioned above, I am no expert so if something doesn't work correctly (likely) let me know.

I have temporarily uploaded it to link below. It should be run on a PC. iPads/Tablets will probably be too slow.


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Old 07-03-2024, 08:08 PM
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Mark_Heli (Mark)
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Mark_Heli is offline
Join Date: Nov 2010
Location: Sydney
Posts: 153
A couple of useful notes...

1. For the go-to functionality to work, you will need to be roughly polar aligned. The better the polar alignment, the better the go-to accuracy will be.
* When the app starts, the scope is already pointing south
* Entering the altitude (based on the observing latitude) will get the scope polar aligned
* You can confirm the polar alignment accuracy by looking at the 'Polar alignment error' and coloured circle.
* Alternatively, you can polar align the scope by drift alignment (pressing T will toggle the reticule)

2. Once the scope is polar aligned, you can go-to a star by selecting the star and the clicking 'Goto Selected'.
* The scope will slew to the selected star
* If you go-to another star, the scope will automatically do a meridian flip if needed during slewing (fun to watch)

3. If you click the sidereal tracking toggle, the sim will automatically track the object.

4. By default, the sim runs at sidereal rate (i.e. the earth rotates once every 23h 56m 4s)
* You can increase the simulation rate using the 'simulation' rate slider.
* If you are tracking an object, the telescope will automatically do a meridian flip once it crosses the meridian (fun to watch).

5. Clicking the 'Goto Home' button will automatically return the scope to the home position

6. You can also look across the sky by changing the dec and ra values.
* The sky has 2 constellations markers - (1) Octans and (2) Orion

Note: The yellow line is the meridian, the green line is the celestial equator and the red line represents an ra of 0 degrees.

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