(meteorobs) October 30th 2012 Fireball Over Southern Mid-West USA

[Chris Peterson]

I believe that the practical difference between the HAD and HAD II 
sensor is pretty insignificant for meteor work. Avoiding color sensors 
is critical, however, if the goal is to detect faint meteors and not 
just fireballs. At 30 fps, sensitivity is largely determined by readout 
noise, not quantum efficiency. At best, the HAD II offers a couple dB 
improvement in sensitivity at normal video frame rates. To achieve the 
maximum sensitivity requires longer integration times, on the order of a 
second or two. Many security cameras offer this (called sense-up, or 
other names), but the feature is not desirable for meteor work, as you 
lose timing information and the increased sky background actually 
results in lower sensitivity to meteors than you see at 30 fps.

Sensors with significantly lower readout noise may prove useful for 
meteor work, but the biggest immediate improvement comes from getting 
rid of the analog video interface completely. Not only does that 
interface typically reduce the dynamic range it's possible to capture 
from the sensor, but the digitization process introduces _significant_ 
geometric errors, which limit the accuracy of calculated centroids, both 
of astrometric references, and most seriously, of meteors. 
Unfortunately, I'm not aware of any inexpensive low-light cameras using 
HAD sensors which incorporate digital interfaces 
(USB/Firewire/Ethernet). When I find one, though, it will quickly find 
its way into one of my meteor cameras!

Chris

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

On 10/31/2012 10:26 PM, Jay Salsburg wrote:
> Hello Jim
>
> Thank you for your inquiry.
>
> I have been performing research on a camera with all new technology that I
> tested in my driveway and successfully observed meteors in its video. Since
> I do not have the money to buy every camera that seems a candidate for a
> Meteor Observatory, I spent many weeks investigating alternatives based on
> published specifications. I found a Camera for less than $200 employing the
> new Sony "Super HAD CCD II" Sensor that sees better than I in the dark and
> in Color (see link below). I will publish details of my design after testing
> it on a high mast if it is fit for the task of recording video of Meteors,
> which I should be able to do soon. I just finished creating a reliable
> Enclosure. There are finishing touches yet to install in and on the
> enclosure like heater resistors, a fan, Connectors, and a Mast Mount.
>
> http://www.sony.net/Products/SC-HP/cx_news/vol52/pdf/featuring52.pdf