Thomas is a YuKonstruct member who loves looking up at the night sky. You might remember his previous post on building a telescope from scratch. Recently, the Klondike Visitors Association purchased one of the allsky cameras he developed and had it installed in Dawson City. It is the first camera in the Yukon Astronomical Society’s future Yukon Allsky Camera Network!
Like a lot of people, I love watching and taking photographs of the northern lights. I always have a hard time getting back in the house and going to bed because I feel that I’m missing out on a great show. “What if there is a geomagnetic storm in the next 15 minutes?” Still, I can’t spend every night outside in the cold. On top of that, I have a day job that requires me to have at least one eye open during 8 hours.
In order to keep my sleep pattern happy and reduce my fear of missing out on the activity above my house, I decided to build a camera that would make a short movie of the entire sky and send it to my website in the morning so that I could watch how active the aurora had been during the night.
Northern lights are large colorful curtains of light stretching across the sky. It’s quite hard to fit them in the frame of a single photograph. Some people stitch multiple pictures or use wide angle lenses in order to capture the whole show. But individual pictures don’t show the way the aurora borealis flows, unrolls, dims and pulsates. Taking a serie of images and making a timelapse video was the only reasonable way for me to capture the whole information.
In order to build such a camera, I decided to use an astronomy camera (ASI224MC). It has a USB connection and is extremely sensitive to low light. I slapped a fisheye lens (180 degrees) on it to view the entire sky. My first thought was to place the camera outside and run a cable to the house computer through a window. I quickly realized it wouldn’t be very practical and it would anger my roommates to pay a huge electrical bill if I left the window open for the entire winter season. Instead, I decided to bring the computer outside. A Raspberry Pi was perfect for the job. It is small but it’s still a computer with enough power. I created an enclosure from a 4” ABS sewer pipe and ran an extension cord to it. That was it for the prototype. I had just built an “all-sky wireless camera”.
But that wasn’t the end of it. The software part was probably the most time consuming. First, I had to re-learn C++ in order to modify the example code that was provided with the software development kit of the camera manufacturer. Then I had to find a way to stitch all the thousand images from the previous night into a short video. Then I had to automate this video generation, archiving and uploading. After some trials and a few fails, I ended up with a fully automated camera that posted a new video everyday based on the time of sunrise and sunset. The only downtime was caused by construction workers cutting the fibre cable down south or the occasional critter frying itself on an ATCO transformer.
In the end, since I wanted to share that project, I posted an Instructable on how to build your own wireless allsky camera. The popularity of the post lead me to share the whole code on GitHub with an very permissive open source license.
Since then, a lot a people across the world have built their own allsky camera based on my design. Recently, the Klondike Visitors Association in Dawson City purchase the first camera produced by the Yukon Astronomical Society.