Polar Alignment with iPad/iPhone

[rat156]

Hi All,

After some adjustments to my mount over the weekend I needed to get things aligned again. I have Starwalk on my iPhone, so I asked it to find Polaris Australis so I could get things roughly aligned. The PMX has a nice flat bit on the mount which make a near square alignment possible. The iPad is a bit big, but jammed up against the rear of the mount seems to work OK.

Please excuse my daughter's shaky photography, this example is with the iPad, couldn't take a photo of the iPhone with the iPhone...

Might work well for a portable setup to get you reasonably close to the pole to start off.

Cheers
Stuart

[mithrandir]

Stuart, the biggest problems with iDevices are that the compass isn't really accurate and any magnetic material anywhere near (eg reo in the concrete) throws them off badly. I've tried using a few compass apps, Star Walk and SkySafari on my iPhone and iPad near where I sit my G11 and the steel pool fence stuffs up the alignment. Doing the figure 8 wave helps but isn't perfect.

For a temporary setup it might get you in the ballpark but the solar noon method works better.

[Steffen]

Yes, I too found that magnetic compasses (iPhone or otherwise) are too inaccurate and can vary by several degrees depending where they are held in relation to the mount. At home I've made several reference lines/points using the solar noon method, and when away from home I try to find a star crossing the meridian around setup time and use that for pointing the mount.

I found however that the accelerometer gives very precise and repeatable results when used with apps like Clinometer. I use that for levelling mounts and setting the altitude tilt.

Cheers
Steffen.

[Poita]

I never have any luck with any kind of compass, but find clinometer is really accurate, and I use the solar noon method to scribe my North South line.