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Messages - John Pierce

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TAC Visual / New NEW ....
« on: August 16, 2014, 03:48:01 PM »
Well, the Drupal forum I tried to foist upon this community failed abysmally.

We're going to use SMF going forward.     If you previously used this SMF board when it was a test, you still have an account here.  if you'd only used the 'drupal' site, then you'll need to register again.   

Sorry about the wretched mess I created.

TAC Visual / Re: Welcome to an experimental new TAC
« on: May 01, 2014, 01:13:18 AM »
testing a couple minor setting changes.

Forum stuff / user profiles
« on: April 30, 2014, 09:21:10 PM »
I made location mandatory on new user registrations, and I added a new field, which is private to the moderators and will be used to help tell people from bots.

On 4/30/2014 4:05 PM, Lynne Jolitz wrote:

 You can't use the sensor information filtered through a traditional java app. Instead you must access the raw data using the C++ dev library access to the underlying raw sensor information at the HAL layer (hardware abstraction layer). This actually got discussed at a Lab 126 talk a few months back.

 If you don't use *and* process the raw information appropriately, the slew lags, making the app too imprecise for your needs.  This is due to the lag induced by the filters and an inappropriate selection of mathematical distribution for use with astronomical equipment. One must use the raw data and then use the correct distribution (in this case, a Kent distribution). Then one uses techniques to minimize delays. It's actually a subtle area of app development  and not the province of script kiddies.

 Hope this helps. I'd like to see a better astro app for this purpose myself. Get developing. ;-)

On 4/30/2014 3:57 PM, Mark Johnston wrote:
> Don't bother reading this unless you are going to try or maybe buy SkyEye.   
> I too have been trying to use compass for android in software app and agree it is a well known serious downfall that  the compass and/or magnetic sensors are in general so bad that you never really know or can count on them to better than 10-30 degrees but can get 'lucky' given certain phones and if you have recently calibrated in the field just before use and at the same place as your scope.
> Yes I know there is an offset from true north as far as magnetic lines of force go but THAT is not the issue here.  People have had all sorts of issues with their sensors getting too much of an offset and having to try to 'degauss' them before they would work at all as I found was just ONE of my issues. 
> I have been working on an app based on Carter Scholz neat little device that is called 'Where is North' which shows where north is in the eyepiece for any given position.    I see numerous posts and agreement that the android accelerometers or not so bad but the magnetic sensors can be very erratic or can be ok and you never know what to believe.  Calibration is not the solution in general. Not repeatable and some phones are reported to be horrible always on those readings.
> forgive me for this off topic post but it does relate to the plug to use this nice little app mentioned.    I have wasted over 12 hours in working with and looking into this issue and is is quite 'sad'.  I hope that anyone who tries it simply goes in knowing that it is likely ok for handheld eyeball gazing but if it actually works for a narrow < 1 degree field of view I can assure you you will be VERY VERY lucky and should buy a lotto ticket that day as that is your lucky day.
> In short, if you have to verify it every time with a compass and re-calibrate X times then what exactly is the point???
> Marko

On 4/30/2014 2:25 PM, Alex wrote:
> The phone's gyroscopes/accelerometers/magnetometers are not stable and not precise enough for the task. I'm developing for the phones and know that for sure, as I have tried to make such a thing myself just recently with the top brand Android phone (Note III).

On 4/30/2014 1:37 PM, Stephen Migol wrote:
> I have a copy of the application on my phone.  Unfortunately, we have the Hetch Hetchy pipeline running through our backyard and the magnetic field from these steel pipes renders the application useless there.  It should work nicely out in the field.  My phone's sensors tend to be jittery so it's not terribly great.  I have a cheaper phone so that may be a big factor.

On 4/30/2014 7:39 AM, Michael Packer wrote:
> Has anyone tried SkEye - an app for Android that uses your phone as a "push to" viewfinder for a Dob. (free on Google Play at
> It works like Google Sky, with the added twist that you can strap your phone to the optical tube of your scope, do an alignment procedure, then use the display on your phone as a virtual viewfinder for your Dob.  It's accuracy evidently depends on the accuracy of the accelerometer(s) and magnetometer(s) in your phone -- some phones are better, others are worse, according to some of the reviews

Forum stuff / Re: Observing intents...
« on: April 30, 2014, 11:39:33 AM »
well, the behind the scenes consensus is, the OI's should remain on the TAC calendar, this also enforces some sanity in their layout (via defined fields for date, location, etc).

actually, we may end up using a different forum than this, integrated into the main website instead of completely external like this one.   c'est la vie.

Forum stuff / Re: smiley test!
« on: April 30, 2014, 11:37:53 AM »
re: GSSP, good idea, how about if I expand it to be major annual star parties so it can do double duty for CalStar?

TAC Imaging / Re: Testing image embedding
« on: April 29, 2014, 10:23:36 PM »
nice!   8)

TAC Visual / Re: Welcome to an experimental new TAC
« on: April 29, 2014, 10:19:47 PM »
oh, and the WAP2 link at the bottom is for phone screens

TAC Visual / Re: Welcome to an experimental new TAC
« on: April 29, 2014, 10:18:35 PM »
I prefer fora vs email aliases, although something that produces feeds/digests would be good for mobile use in the field.

A) Click the 'Notify' button at the top of a forum, and you'll get email notifications of all postings in it.

B) there's an RSS link at the bottom.


TAC Visual / Re: Welcome to an experimental new TAC
« on: April 29, 2014, 10:16:55 PM »
The new forum looks great.   And is easy to use.

What needs to be tested?

well, its not integrated with the website.  needing separate registrations is messy.

btw, I just tweaked the style a bit, didn't like the brown links, so they are blue now...   or the fade, so I added a starfield (a DSLR widefield from GSSP 2012).

Forum stuff / Observing intents...
« on: April 29, 2014, 09:56:44 PM »
should Observing intents be on the web site's drupal calendar, or should they be postings on an OI forum ?

what do you guys think?

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