The Tucson-based SALSA Meteor Camera
August 15, 2009 1 Comment
The SALSA systems are my camera set-ups for the autonomous detection of meteors. SALSA is a rather tongue-in-cheek acronym that stands for “Search for Alien Lights over Southern Arizona”. And it does a great job of detecting “alien lights”. In addition to meteors, the camera also detects lots of birds, bugs, bats, airplanes, helicopters, clouds and the occasional flaring satellite. Every morning I need to examine the data and toss out the non-meteor detections.
SALSA is based on the Supercircuits PC164CEX-2 video surveillance camera. The camera is equipped with a 1/3″ Sony ExView CCD detector. The camera produces a 60 Hz video signal, meaning 1 image every second though only every other image is analyzed by the meteor recognition software. The cameras are small and designed for low light level survelliance. They are also relatively cheap at ~$130, that is compared to most astronomical cameras.
Originally, I used the Supercircuits PC164C camera which is not as sensitive as the PC164CEX-2. Many meteor observers use the Watec 902H2 Ultimate for their observations. Those cameras have larger detectors which allow one to either cover more sky than the PC164CEX-2 or to cover the same amount of area but with a larger lens allowing more one to detect fainter meteors. They are also more expensive (~$310) which is why I have been using the PC164C series cameras. In the future, I will probably upgarde to the Watec cameras.
For lenses, I use Computar 4mm f/1.2 1/3″ lenses (they usually go for ~$15-50 on Ebay). The camera/lens set-up gives a FOV of ~50×60 deg down to ~2nd-3rd magnitude. So nowhere near all-sky but it gets me enough meteors to monitor the showers.
The cameras are part of the International Meteor Organizations Video Meteor Network which is run by Sirko Molau of Germany. Sirko wrote and provides the automatic detection software called MetRec (which is free). Sirko also collects all of the observations and publishes monthly and annual summaries.
You can read more about the software and the network here:
IMO Video Meteor Network Homepage
MetRec software homepage
IMO Video Meteor Network Monthly reports
The software only runs with Windows 98 (though a version that runs on more modern Windows distros is in beta testing). MetRec also can only be used with a Matrox Meteor I or II card. It is this requirement that is the most problematic since the cards are no longer made and must be purchased used off of EBay (~$150, though lately some have been going for much cheaper). Sirko usually has a number of these cards available for purchase.
Other than that, I have an all-weather surveillance camera housing so the camera can survive the elements and use regular S-video cables to connect the cameras and computers.
The MetRec software runs all night without any supervision. It is good at picking up objects moving at meteor rates (including planes, bugs, bats, clouds…). In the morning I go through the detections and identify the actual meteors (that can take from 5-15 minutes).
MetRec also identifies which shower, if any, each meteor is a member of.
Bob’s camera set-up includes an image intensifier and can be seen here.
As you’ll see from the above webpages, this is mostly a European operation. Bob and I are the only US members. We could definitely use more cameras over on this side of the Atlantic.
There are also a large number of all-sky fireball cameras throughout the US. They are part of the Sandia Research Lab’s Sentinel system.
These system don’t detect meteors as faint as the SALSA cameras but they do cover the entire sky. As a result, this system is great for detecting large bright fireballs especially ones that can produce meteorites.