Happy new year! Another year means another year-long keogram! Every 15 seconds throughout 2022, my trusty all-sky camera took a picture of the sky above the Netherlands. Combining these 2.1 million images into a year-long keogram reveals this picture, which shows the length of the night change throughout the year (the hourglass shape), when the Moon was visible at night (diagonal bands), and the Sun higher in the sky during summer, as well as lots and lots of clouds passing overhead.

@cgbassa Nice!
I was playing around with a similar idea in 2017, but only using a single pixel sensor to grab the average colour of the sky.

I need to revisit this, my set-up wasn't as weather proof as I thought it was, so only got ~8 months of data.

@Dtl That looks great and nicely shows the hourglass shape. I'm also intrigued by the steps during sunrise/sunset? Is there some exposure control going on?

@cgbassa I think it was picking up a lot of neighbours lights.
The colours go strange towards the end because the weather proofing failed and the sensor got damp (I didn't know at the time).

How's your camera constructed?

@Dtl I'm using a waterproof box and an acrylic half dome sealed with silicone. A 2 port relay powers the dew heater in the dome and a fan in the enclosure, controlled by the PoE powered RPi3B+. The camera is a ZWO ASI178MC. Initially I had planned to use the fan/dew heater when needed, but after a month or so I just left them on continuously. The bearing on the fan failed this year, so the fan was replaced.
@cgbassa Thank you.
I was using an old CCTV camera box, but it wasn't good enough.
@cgbassa how much would you say this setup would cost to set up?
@Dtl
@FiXato @Dtl Probably a few hundred euros. Most expensive will be the camera (ZWO ASI178MC), followed by the RPi. But there are cheaper setups as well, see what others have built at https://www.instructables.com/Wireless-All-Sky-Camera/.
Wireless All Sky Camera

Wireless All Sky Camera: An all sky camera is a device designed to take pictures of the entire sky over a certain amount of time, usually to monitor meteor showers or other astronomical phenomena. I built mine to monitor the northern lights. I live in the Yukon and we some…

Instructables
@cgbassa thanks. :) Would be interesting to see with the midnight sun in Summer, and very short days in Winter, here in #Bodø, Norway. :)
@Dtl