(meteorobs) OT-Possible single station determinationofmeteordistance.

[Chris Peterson]

There are two ways you can mix video signals. You can use a pair of cameras 
that share a common timebase. Some cameras allow an external sync from 
another camera, but it isn't a common feature. It isn't too hard to 
implement yourself, but it does require some fine assembly and the running 
of signals between the two cameras. The other approach is an external 
circuit that delays and rebuilds one signal to be in sync with another. This 
isn't very simple.

I don't think it matters, however, because I don't think your approach is 
practical. The method depends on measuring parallax, and at the distances 
involved the parallax is just too small. The position shift between your 10 
mile reference and any meteor will not exceed about 20 arcsec, which is 
going to be very difficult to detect. You will need very high quality 
lenses, you probably can't use protective domes, and your astrometric 
calibration will need to be almost impossibly good. The angular separation 
between the images from the two cameras for a meteor 70 miles away will be 
about 3 arcseconds. That is on the order of 1% of your pixel spacing. That 
is simply not measurable with this setup. Even good lenses are not 
distortion free at that scale.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "stange" <stange34 at sbcglobal.net>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: Wednesday, December 17, 2008 4:11 PM
Subject: Re: (meteorobs) OT-Possible single station 
determinationofmeteordistance.


>I was reviewing M&M + light speed for "ideas" of how to EASILY make a
> ranging device that was cheap and simple. I ruled out split image and
> mirrors as being totally impractical and could not find any sound idea 
> using
> that material for what I wanted.
>
> At present the only concept that I think is workable & easier, is
> investigation into reverse autoranging using two cameras. The idea seems
> sound, but whether it can be made practicle and can stand alone in 
> operation
> is the difficulty.
>
> It can be done with a memo-scopes or a dual trace trigger and other ways 
> but
> stand alone multiple triggering with hard drive storage is key functions
> needed all night long to be realistic.
>
> My tests this afternoon on reversing the splitter determined two identicle
> cameras nearly synched in a lock-on but repeated out of phases would cause
> thousands of false triggers with a capture program. So that is the 
> problem.
> "HOW" to get automatic overlays or two image captures AND storage of 
> stable
> events without 2 computers running independantly with split capture and at
> no cost to the user like having to double up on capture cards & having a 
> two
> processor computer. A hardware Engineer is needed here or someone to 
> follow
> up on anything with what little merit I have given.
>
> Basic dwg. illustrating the simple principles without ccd diagonal measure
> correction.....
> http://www.geocities.com/stange34@sbcglobal.net/Distance
>
> YCSentinel