From: Milton Aupperle <maupperl@shaw.ca>

Date: November 8, 2012 10:00:16 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: ONAG Review

Hi Tim;

On 7-Nov-12, at 9:08 PM, doobisary wrote:

Here's a cool potential use of a combination of Astro IIDC and an ONAG that I've thought about, but don't have the time/resources to implement at the moment (but one of these days!):

Use the ONAG and a pair of firewire cameras to keep the scope centered on Jupiter with one while the other takes a multi-hour video of Jupiter, to monitor for impacts. One could set the frame rate to 1fps, which should be short enough to catch an impact but not so high as to make the video file unmanageable (for searching for flashes later). Even better would be if, say, 10fps could be acquired and combined on the fly to produce a sharper frame for that second than a single fram might provide. But I don't know if Astro IIDC could do that.

Actually you can guide and record at the same time with one camera via an AppleScript now. From page 116 of the Astro IIDC Manual:

- Astro IIDC can track and guide while grabbing frame(s) or record movies at the same time using one camera, for example tracking on Jupiter so that you can record the motion of it's moons over several hours. Basically once the mount and camera are tracking an object, you can then execute Apple Scripts that record a series of movies (see "RecordMultipleFrames" script in the .dmg Other Folder example), grab a frame or even stack and align frames (see "Live Image Alignment Method" page 30 for details) while it continues guiding. For best results, use 5 or more for pixel tracking accuracy, so that it does not need to continuously make corrections as you just want to keep your planet reasonably centered.

Some of the people on the list are guiding on a sunspot and imaging it using an AppleScript to automatically take movies / images over hours of time.

I'm not sure that the "Live Stacking", is what one wants though for detecting Impacts on Jupiter or the dark side of the moon. You would be better off recording at 5 to 10 fps and then post processing the resulting movies - if there was an App that could do that (there won't be in the App Store either).

About 15 years ago, I wrote some some code to analyze DV movie footage that I would record with DV Camcorder for Leonide meteor shower. The code would then make a reference movie clip of what it "thought" was a meteor, and include a 1 second before and 1 second after the event stopped. It worked pretty well except for planes. QuickTime is officially deprecated in Mountain Lion now and will be excluded going forward. Apple's AV Foundation only supports MP4 (no reference movies) - along with uncompressed or Video with more than 8 bits per pixel depth either.

TTYL..

Milton J. Aupperle

#1106 - 428 Chaparral Ravine View SE.

Calgary Alberta T2X 0N2

1-(403)-453-1624

maupperl@shaw.ca