(meteorobs) OT -Question to the UFOCaptureV2. -PAUL PUGH et.al.,

[Francisco Ocaña]

Hi,

Larry wrote:
> This 
> starting position is excellent for meteor radiants and total meteor counts 
> using the "T" image....but not magnitude. The .avi's are flawless.
>
>   
Well the UfoAnalyzer tool allows you to determine the magnitude of each 
event. This is not easy because you never have more than 20-30 
references, most of them saturated or undersampled. Remember that most 
of our CCTV cameras have a very tiny dinamic range (30 - 45 dB). If the 
fireball is within this range (it does not saturate), UfoA may be able 
to determine "accurately" its magnitude. However brighter events are 
always wrong estimated.
> (I believe) great care must be excersized on Scintillation Mask and Frame 
> shift settings. Both can cause clipping on leading edges & trailing edges of 
> a meteors weaker ablation. I understand that frame shift value determines 
> how far back in the frames UFO looks in determining a trigger or ending a 
> triggered .avi.... (IF) Head & Tail are short values. I will continue to use 
> 30 (1 second) on both and examine that function more closely later.
>   
30 is ok, but 60 will be too (if you don´t have RAM or HDD 
resctrictions. Stacking 120 frames will give you more reference stars ( 
I think if you double the time you get 0,75 magnitude deeper).
> I will NEVER use Slow Object masking. I need the plane trails and also will 
> not risk losing any part of slower fireballs. Another area of further 
> investigation....
>   
Never say never, jeje. I use plane trails to confirm it works, however 
the slowest ever fireball will be faster than 80% of the planes. I have 
everyday 15-20 planes crossing the field for more than 25 seconds. That 
means 400 seconds or almost 2 Gb of planes.  How do you manage them?
> UFO  uses the same model card without these defects.
>   
And about Frame Grabber Cards... which do you (and other UfoCapture 
users) use? I use a chip USB one, and I want to upgrade to a PCI one. 
Any ideas?

Best,

Paco