Polar alignment with no line of sight to Polaris

[Arion]

Given that I'm in the middle of a moderately big city, there's a pretty decent observation point in an empty guest room under the roof of our house for when I don't feel like driving out. It's just above most of the surrounding buildings with a great open view south, away from the city center. The only downside is that setting up the telescope on the southern side of the house makes it impossible to see Polaris. There's a roof in the way.

What's the best way to get the most precise polar alignment without line of sight to Polaris? Using a compass and the latitude adjustment should give me the general direction, I believe, but is there a way I could get it more precise than that?

[Guest]

Drift Alignment with PHD2

 

 

https://openphdguiding.org/tutorial-drift-alignment-with-phd2/

[RolandKol]

I had the same problem, PHD2 drift alignment helped a lot, but... it was not really helpful initially as the mount missed quite drastically and RA/Dec bolts were too short to make a proper adjustments. Before you go for PHD2 drift procedure you may do some preparation steps I did:

1) Once you turn on your mount, and if Moon is visible, slew to the Moon and if mount misses, use RA and DEC to target it on it.

2) If your Mount was way Off the North, you may need even move the whole tripod to adjust it correctly (even re-level if needed).

3) Once you will be able to catch Moon in the target from Home position, - go ahead with Drift Alignment.

P.S.

You can use a bright Star instead of the Moon, but if your mount does not miss a lot, if it Misses a lot, before the procedure, properly align Finder Scope and use it for targeting at the start.

[Arion]

Oh yeah, I am talking about an all manual mounting. Kind of important detail I forgot to mention, I guess.

[Davey-T]

1 hour ago, Arion said:

Using a compass and the latitude adjustment should give me the general direction, I believe, but is there a way I could get it more precise than that?

That should be good enough for visual.

Dave

[Arion]

It's more important for long exposure photography, right? To avoid smears.

[RolandKol]

1 minute ago, Arion said:

It's more important for long exposure photography, right? To avoid smears.

Yep,

for visual, the compass is enough.

[Davey-T]

1 minute ago, Arion said:

It's more important for long exposure photography, right? To avoid smears.

Even astrophotography can be done without perfect polar alignment it just puts less strain on the guiding

[NGC 1502]

 

Agreed, for basic observing, near enough polar alignment is adequate.

For a regular equatorial mount -

Just set your latitude as best you can on the zero to 90 scale.  Point the polar axis north as best you can. All done.

In use, as polar alignment is approximate, your target will drift north or south within the field of view as you track in RA. Just give the appropriate tweak on the declination control.

Final step - enjoy the view ?

Ed.