iPhone Digital setting circles quest.

[marcopolo]

Hi all,

i'm new on the forum today so be gentle!!!!!!!! i've put up a small bio in the introductions section.

I'll cut right to the chase then. i'm persuing using the iphone as a digital setting circle; a cheap replacement for more expensive items like Argo NAVIS, JMI ETC....

I'm a mech. engineer and like a dog with a bone I wont give up until I get this working!

So first to previous attemps. Using the search here i've seen people try similar with pointing devices like skyscout and the iphone3 but there are severe shorcomings like delay when moving the scope, poor apps for angles and compass etc..and just general innaccuracy. However these post are prior to to important developments, namely the iphone 4 has a gyroscope which makes the angle meters much more accurate and responsive and secondly, this superb little app:

http://hrtapps.com/theodolite/ which is basically an augmented reality 3 axis anglemeter/theodolite to 1/10th degree. I've used the app for over a day now and it's very accurate comared to my Wixey digital angle guage which I use on my Scope in conjunction with Starmap Pro (which by the way nearly always lands me my object in my widefield eyepiece on Elevation and some azumithal hunting.)

So now how to use it on the scope. My scope is a composite/wood/alumiinium 8.75in F5.8 Dob. So i'll need to make an iphone mount. Clearly the mount cannot be made from metal and the mount must standoff the scope a descent amount to not be near any steel fixings - all this so the the compass calibration is not thrown off. Clearly with a metal telescope tube this task is going to be more difficult. What i'm not sure about is whether or not steel has more of an effect on the iphone compass than aluminium?

I'm willing to bet that I can get it working and put the object in my 40mm Plossl (3ish degree field). However another problem which requires a third pary to get excited and I don't think they will unless I get this working!! I will have to switch apps between Satrmap Pro and the Theodolite each time I use it. So if I get reasonable sucess, i'm going to contact the makers or Starmapo pro, explain what I did along with my results and see if they would be interested in either making a standalone program that works exactly like a set of digital setting circles with a database of objects as this doesn't even need a starmap - just simply a menu with objects and arrows to push the scope, or incorporate into Stamap pro in a 'navigate mode'.

In actual fact the compass doesn't need to be as accurate as the angle meter because once you know your Elevation (attitude) is correct, as long as you are in the general area locking the object in azimuth is fairly easy with a few sideways wiggles of the scope.

As far as I can tell all the tech is there. It just needs exploited. If it works it could save a serious amount of money and for the causal observer it would be superb. I should add a spent 18 years of starhopping from an atlas and in Scotland mid February 3am at minus 10degC it is much more fun to use the (insulated from the cold) wixey digital guage over starhopping. I at least double the amount of objects I see.

Wish me luck and i'll try get this started by September (very busy just now!!). Cheers,

Marco

[Pingster]

Good luck! Its a great idea and starmp is excellent.