(meteorobs) Rarity of daylight fireball recordings.

[Chris Peterson]

There are, of course, as many nighttime earth grazing fireballs as 
daytime. Regardless of the type of fireballs you hope to capture, adding 
daytime surveillance nearly doubles the time you are watching, and 
increases the number of actual captures by something quite a bit less 
than that. All quite worthwhile, of course. You might record a handful 
of daytime events in a year.

You will cut down the captures significantly if you use a narrower FOV 
camera, however. A standard daytime allsky camera design exists, and can 
even be purchased commercially from weather instrument makers. It can 
also be made quite easily. It requires nothing more than modifying an 
ordinary allsky camera to provide a sun occultation disk. You use a 
clock with a 24-hour mechanism to drive a wire and disk around the 
camera, tilted to match the ecliptic. You have to manually adjust the 
tilt every couple of weeks, but otherwise it takes care of itself.

The only other issue with daytime meteor monitoring is that dealing with 
the collected data is more time intensive. There are simply many more 
things in the sky during the day that generate false alarms. Of course, 
that problem could be addressed somewhat with smarter detection 
software. But most code right now isn't much better than simple motion 
detection, and there's a lot moving in the sky during the day.

Chris

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


----- Original Message ----- 
From: <stange34 at sbcglobal.net>
To: <meteorobs at meteorobs.org>
Sent: Saturday, May 17, 2008 1:33 AM
Subject: (meteorobs) Rarity of daylight fireball recordings.


> An opportunity might exist to record daylight fireballs, and the 
> larger rare
> earth grazing fireballs, if standard surveilance cameras (non-all sky) 
> are
> used in a manner to avoid much of the sunlight with the smaller field 
> of
> view and CCD chip dimensions which produce rectangular imaging 
> deliberately
> oriented to minimize solar glare which can mask a fireball.
>
> Construction has been started to augment the Sentinel facility here in
> Northern California using handyavi software for recording, and
> inexpensive(under $25) Sony 0.1 Lux Hyper HAD model SPT-M124 B/W 
> cameras
> obtained off of ebay. Most have lenses attached.
>
> Others are encouraged to try daylight capture techniques to share 
> solutions
> to common problems in daylight glare masking & any additional areas of
> concern.
>
> The global search subject of "daylight earth grazing fireballs" on the
> internet is quite interesting.