(meteorobs) Surprising similarity of Meteor streaks & Bolides?

[Chris Peterson]

> Likely a VERY costly & specialized CCD camera.

Not really. The sensors in many video cameras are the same as used in 
long exposure astroimaging, and these have dynamic ranges on the order 
of 72dB, or 12 bits. It's generally the digitizing hardware that is 
limited to 8 or 10 bits, and most video file formats only support 8-bit 
data. But it isn't all that expensive- a few hundred dollars- to put 
together a 12-bit video system. Even so, that's still not enough dynamic 
range to avoid saturation with a big fireball, which might span 14 
magnitudes or more (110dB, 18-19 bits). Cameras with this dynamic range 
don't exist, at any price. You'd need to rig up something with a fast 
iris and some tricky control circuitry, or use two or more cameras each 
with different sensitivity ranges.

But actually, just fitting the fireball profile to a Gaussian largely 
solves the problem, since the shape of the image outside the saturated 
area contains enough information to reconstruct the peak with reasonable 
accuracy.

Chris

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


----- Original Message ----- 
From: <stange34 at sbcglobal.net>
To: <meteorobs at meteorobs.org>
Sent: Thursday, May 01, 2008 10:34 PM
Subject: (meteorobs) Surprising similarity of Meteor streaks & Bolides?


> Understood Chris. Thankyou. Good stuff!
>
> It appears from what you have said that Limovie graphing would be much 
> more
> accurate if the CCD substrate had deeper pixel well depths to give the 
> CCD a
> wider working range of meteor core intensities without early pixel
> saturation.
>
> Likely a VERY costly & specialized CCD camera.
>
> YC Sentinel