As part of the open-source Raspberry Pi Meteor System project, I’ve designed and printed out a number of different cameras that we use daily to determine the orbits of (mostly) small meteoroids burning up in our atmosphere. I use 3DPC PETG for this and couldn’t be happier with the results.
Here are a few photos. The first, eight-camera system is called the Hedgehog and I’ll be the first to admit that the print quality is suspect. I found it nearly impossible to tune Cura to my printer, but, after switching to PrusaSlicer, the quality has improved significantly.
The system works quite well. I’m not sure if you’re familiar with astronomy or not, but the stellar magnitude limit with a 4 mm lens is about 6 at 25 frames per second. Or about what would be visible with the naked eye at a really dark site. The meteor peak limit is about 3.5 to 4. With the longer 8 mm lens we gain about another magnitude or so. Astrometrically, we’re good to about a 1/3 of a pixel in most cases. This is comparable to (or better than) the ‘professional’ systems that we also run at orders of magnitude less cost. About $300 (if you build your own) per camera vs the 3-30+ k that some of our other systems cost.
Right now, there are something like 500 RMS cameras in operation in 30+ countries that have given us about half a million orbits. I’m a bit biased, but it is a pretty amazing citizen-science project that has produced a lot of good data that we’re able to use professionally.
Mike
p.s. Here is a stack of frames from the 2020 Perseid meteor shower…
My bad. You asked ‘how does it work?’, not ‘how well does it work?’
To answer that, it’s basically just an IP camera module using a Sony Starvis sensor and a fast lens (4 mm, f1 is standard). The camera is then connected (through a POE injector) to the ethernet port on an RPi. The software running on the Pi automatically begins collecting frames from the camera about a half-hour before dark and saves them in a special compressed format that we use. Stars are automatically detected to update the photometric and astrometric solutions. Moving-object detection is also automated and can be tuned for different types of objects (e.g. satellites or meteors). After processing is complete, the results are uploaded to our server at Western University where they’re correlated with other observations to compute orbits. This data is then made available on the Global Meteor Network website.
Both these posts were very informative, thanks. Theres been a few open source, printed projects for telescope and tracking devices ive looked at. It’s interested me for a long time and I live where there is a dark sky area nearby about 45 minutes away so its always on my mind to get into this as a hobby
Yes, there are some nice looking trackers on Thingiverse that will take a small payload (like a camera) that I’d like to build myself. With a good, moderate focal length photographic lens on one of the inexpensive cameras from a company like QHY you could take some wonderful wide-field images on a budget. Having a dark-sky site nearby is definitely a bonus. Even if you have some light pollution, there are a number of filters that can help with that. I find that my only problem is coming up with the time to print all of the neat things that I’d like to print. Like the Dora Goodman camera designs that have been open in a browser tab for the past year.
The work that I do focuses on the small stuff. I have worked on telescopes where we’re looking for the big stuff that would result in a ‘bad day’ for us, but our meteor research focuses on things in the few tenths of a gram to a few kg or so in size. The vast majority of the meteors that these systems see will be on the small end with a few larger ones that result in a fireball and possibly meteorites on the ground. We track their orbits to try to understand where in the solar system they came from, how their orbits have evolved to get to us, and the impact risk for hardware and ‘software’ (humans on spacewalks) in the near-Earth environment. Using the meteoroid models from made optical and radar measurements allows those controlling satellites and human activity in space to mitigate some of the risks. Plus, it’s just kind of neat to be able to record the tracks of little specks of dust moving at 10’s of km/s when they’re a hundred or so km away.
I have a bookmark saved. I haven’t set up my darkroom here yet but as soon as I do I’ll trot out my old cameras and especially want to do larger format b&W … too much work recently
