An SQM? What for?

The sky quality depends heavily on the quality of the night, but also on the altazimuth coordinates in the sky. The advantage of SQM is therefore twofold:

• creating a sky map to identify the best portions of the sky

• measuring the Magnitude Per Square ArcSecond (mpsas) for each photo, in order to select only the best ones

For this second reason, we decided to mount the SQM on the telescope, in order to measure the MPSAS in the portion of sky photographed. We could have located the SQM in a fixed position in order to compare the quality of each night, but the altazimuth information would be missing.

Code

The code is 99% copied from this source:

https://github.com/gshau/SQM_TSL2591

However, I faced an issue that forced me to modify the code. Approximately after 5 seconds, the Arduino loops were stopped. My code is full of comments from dozens of failed attempts, and doesn't deserve to be copied here! If you have any questions, feel free to email us at the address provided in the contacts.

Enclosure

The enclosure was 3D-printed, enabling different positions of the sensor. The difficulty is to locate the sensor exactly at the right focus point of the plastic lens. Not an easy job, since it must be done in the x,y,z directions. If you need the 3D plans, just mail us