(meteorobs) Determining physical dimensions of a large fireballin the sky?

[Larry]

I believe your spreadsheet would be a (very) useful and important asset to 
both observers and all-sky camera operators of Meteorobs Pat!

Would close camera alignment of True North(< 1 degree error), and a close 
scaling of Altitude(+- 3 degrees) be sufficient to do this? Or does it also 
require a close event time START and STOP synch between the 2 independant 
cameras?

Larry
YCSentinel





----- Original Message ----- 
From: "Pat" <pat_branch at yahoo.com>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: 2009/10/13 05:30
Subject: Re: (meteorobs) Determining physical dimensions of a large 
fireballin the sky?


> With a single video capture you can't do much with it. You might be able 
> to get velocity if you have some other verbal sighting tracks...but mostly 
> you get velocity relative to the camera. With two or more videos you can 
> get absolute velocity and some ideas of size. Since you can get 
> deceleration versus altitude with two or more videos you can get estimates 
> of size. If you recover material and get composition then you can tell 
> even more. There is a paper by Ceplecha in the BAIC volume 48 page 222 
> called "Geometric, Dynamic, Orbital data...from Fireball Networks". It is 
> available on the NASA ADS system. You might read it. They have a software 
> program called FIRBAL that does the numbers for them from calibrated 
> cameras. One of these days I am going to make an Excel Spreadsheet that 
> given the azimuth and elevation from 2 locations will calculate the 
> trajectory and landing locations. I have it now for a simplified (linear 
> path, constant velocity) solution, but working on getting a more general 
> solution. I will put it in the files section if I ever get around to 
> finishing it.
>
> --- In meteorobs at yahoogroups.com, Thomas Ashcraft <ashcraft at ...> wrote:
>>
>> Here's another question for this forum:
>>
>> Can the actual physical dimensions of a fireball in the sky be
>> determined with accuracy from video captures? I am not referring to
>> brightness magnitude in this question but rather to the dimensions of
>> the meteoroid/meteor itself before and during its burn.
>> .
>> Thomas Ashcraft
>>
>>
>>
>>
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