Aligning an AZ Goto mount during daytime

[lukebl]

I'm planning to go to the total eclipse in August, and have been testing my Skywatcher AZ goto which I intend using to track my camera.

The obvious problem is how to align an AZ mount during the daytime, so that you can track the sun, when no alignment stars are visible. So I've come up with this rough-and-ready way of alignment using the approximate location of Polaris, which seems to work.

1. Level the mount
2. Plug in the power and go to 2-star alignment.
3. Select Polaris as your first alignment star
3. Point the camera/scope due north (I used a compass) and at an angle equal to your latitude (using the 0-90 degree altitude scale on the side of the mount). i.e. roughly pointing at Polaris.
4. Click OK
5. Select a second alignment star (for convenience I chose one near the sun). Allow it to finish automatically slewing to the (invisible) star, and press enter when it's done.
6. Check the tracking speed (i.e solar etc), and slew to the sun.

Obviously it's not wildly accurate, but it seems good enough to guide on the sun for a reasonable amount of time. This morning the sun remained roughly central in the field of view for at least 30 minutes. So, with software to automate the captures, I should be able to leave it get on with the job whilst I enjoy the spectacle.

If anyone knows a simpler or more accurate method of alignment, please let me know!

Here's a quick capture from this morning using my PST and QHY5 cam. Some nice prominences at the moment.

[ronin]

One problem may be pointing North by the use of a compass. The difference between True North and Magnetic North can be a lot, one person found there was a 13 degree difference. I know one bit of the world (North America as it happens) where magnetic North is flipped and so the N bit points more or less South.

So where it is you are going to be find out this difference (Magnetic Declination).

Also get to where you want to be about 2 days early, I seriously doubt that it will be anything other then total gridlock, and as was pointed out get the electronic visa thing done now.

Not sure if on a Skywatcher you cannot just aim North and tell it to use that without the dummy 2 star alignment, have an idea that you can. Would save a bit of messing around.

[darknight]

any way you could use gps to determine exact co ords, using a star program. skytech x or cdc for example?

[lukebl]

I know that using a compass for North is not at all accurate, but my point was that this method seems to give sufficient accuracy to guide for 20-30 minutes without attention.

I am booked into a site in Wyoming two days before the event, so will have time to settle in and perfect my technique!

[Cornelius Varley]

The latest version of the Synscan firmware has a solar tracking function.

1. A "Solar Track Mode" is added in the UTILITY menu.
   To use this new function:
   1) Polar align the equatorial mount or level the base of the Alt-Az mount.
   2) Finish the initialization on SynScan. No alignment is needed.
   3) Activate "Solar Track Mode." Now the mount will start working at solar tracking speed until exiting the "Solar Track Mode".
   4) Center the Sun in FOV with SynScan hand controller.
   5) Start observing.
   Warning: Your telescope must be capable of observing the Sun safely.

[ronin]

I agree the accuracy does not need to be great, I was tracking the Sun a few days back and I had to guess North, did have a GPS compass but it was so obviously wrong I gave up - why with GPS do they still use a megnetometer?

Something was even then still wrong as the scope still pointed a fair way off the sun - suspect DST owing to the amount it was off, seemed about 15 degrees. So like yourself I manually slewed to the sun and the scope tracked it happily for the next 30-40 minutes, and the eclipse will not be anything like that long.

There is an Easy Track option on the Synscan, basically level the thing and aim the OTA at True North, then somehow select Easy Track. Page 6 snf 7 of the Synscan manual refer. Might just be a little easier, or less buttons to press.

Get a few pictures of the roads when you are there, really expect it to be cars, cars, SUV's, SUV's and RV's everywehere. Maybe a tank or two also.

[lukebl]

9 minutes ago, Cornelius Varley said:

The latest version of the Synscan firmware has a solar tracking function....

Mine already has a solar tracking mode. Are you thinking of the EQ/AZ mount? Mine's just the basic AZ GOTO. This one:

Anyway, I  can't upgrade the firmware as none of my computers can recognise the handset, despite all my efforts. They recognise my NEQ6 handset, but not my AZ one.

[lukebl]

20 minutes ago, ronin said:

Get a few pictures of the roads when you are there, really expect it to be cars, cars, SUV's, SUV's and RV's everywehere. Maybe a tank or two also.

Yes, I am dreading the experience. I anticipate utter chaos! However, I'm staying on a ranch which is only providing space for about 20 RVs. Some folks are trying to charge thousands of dollars for accommodation!

[Cornelius Varley]

The Synscan firmware is compatible with both EQ and AZ mounts.

[DirkSteele]

Back during the 2004 Venus transit I just let the Alt-Az mount do a two star alignment and I just confirmed the star position when the scope beeped at me to do so.  Even though it clearly would not be up to scratch for finding DSOs in the night sky, it was more than sufficient to keep the sun in the field of view for hours.

[lukebl]

Thanks all for the input. 

I've updated the handset with the latest firmware and I notice that there are a few additional features, including Daytime Alignment.

I thought 'Brilliant. Just what I need!'

However, it is completely useless! It just gives you the option to align on 5 selected bright objects: Jupiter, Mars, Capella, Aldebaran or Vega.

True, if you know EXACTLY where they are you might be able to pick them up with binos. BUT. The whole point is that you can't see them BECAUSE ITS DAYTIME! 

Also tried the 'Solar tracking mode', but it didn't track the sun at all. Can't see how it could if you haven't managed to align it.

[Geoff Lister]

Synscan has a "Park" function, and, if used prior to shutdown, gives you a "restart from Park" option. The "Home" option leaves the OTA level (ALT = 0) and pointing North (AZ = 0).

Would it be possible for you to align the scope at night, select park, turn off, and leave the assembly in place until you wake it up again for the daytime viewing?

[IanL]

Bit surprised at your description of daytime alignment. I have an AZ with V3 handset and the most recent firmware. After completing the initialisation (date/time, location, etc.) i just choose 'yes' when asked if I want to begin alignment, and then scroll down to the third option, 'Daytime Alignment'. The handset says 'searching' for a couple of seconds and then gives the coordinates of the Sun and asks you to point to it it.

After doing so there is another (slightly redundant) step asking to centre the sun in the eyepiece and you are then good to go. Just go to 'tracking' and select 'solar rate'.

The Sun stays in the eyepiece for hours with only minor tweaks needed depending on how level the tripod is 

[lukebl]

9 minutes ago, IanL said:

Bit surprised at your description of daytime alignment. I have an AZ with V3 handset and the most recent firmware. After completing the initialisation (date/time, location, etc.) i just choose 'yes' when asked if I want to begin alignment, and then scroll down to the third option, 'Daytime Alignment'. The handset says 'searching' for a couple of seconds and then gives the coordinates of the Sun and asks you to point to it it.

After doing so there is another (slightly redundant) step asking to centre the sun in the eyepiece and you are then good to go. Just go to 'tracking' and select 'solar rate'.

The Sun stays in the eyepiece for hours with only minor tweaks needed depending on how level the tripod is 

Very peculiar indeed.

I have uploaded the latest firmware and it definitely doesn't offer the sun as an alignment object. It even offers Mars (mag +1.3) for alignment. Completely useless for daylime alignment!

[Cosmic Geoff]

I often use the Sun as a daytime alignment object with my Nexstar SLT mount. First, you have to enable the Sun as an alignment object somewhere in the setup. Accurately level the mount/tripod. Then select Solar System Align, select the Sun as an alignment object (ignoring warnings), coarse align on the Sun using the shadow of the 6x30 finder and then the projection of the image on my hand. For fine align I can see the exit light illuminating the dust on the main telescope eyepiece exit lens (DO NOT LOOK THROUGH IT).  Quickly  complete the procedure and slew elsewhere or cap the scope. Now ready to find Venus or whatever.

The Synscan should have an equivalent procedure. Please note that this is not without risk - if you make a mistake you could damage your eyesight or melt a plastic eyepiece.

[cathalferris]

I used have an ETX-70, and I was able to align pretty much every time in the daytime by doing the following:

1. Level the tripod, such that the mounting plate was level in all directions.
2. Attach scope to tripod, approximately north.
3. Switch on, and perform a fake alignment, just selecting "okay" when prompted for stars.
4. Select something bright such as the Moon or Jupiter or the Sun, and goto.
5. Loosen the azimuth clutch and sweep by hand in azimuth until the bright object is in view, and re-tighten the clutch. The goto will have set the appropriate altitude if the level and location were correct. If needed, zero in by loosening clutches and moving by hand, as the handset thinks that it is already pointing at the target, you're just ensuring that this is the case.
6. Done.

I could align on the Moon and then goto Jupiter and have it in the eyepiece, then goto Saturn. Saturn was hard to see against the background of the sky, but mag 0 and 1 stars were possible daytime. It's a nice party trick.

This method of daytime alignment relies on the build quality of the mount to be good enough that the azimuth plane is close to the tripod plate, and that it's possible to loosen the azimuth clutch. At least with the FOV of the ETX, it wasn't that big of a deal.

It should be easy enough to get your scope day aligned by either using this method or adapting it to the specifics of your mount.