Seeing Monitor

Being an avid imager, knowing the seeing conditions is crucial for capturing sharp images. For a long time the seeing conditions was only known after an image was taken. There have been commerical seeing monitors available over the past decade or so. But they were pricey and not widely known. The most popular of these was sold by SBIG and was initally called the SM-1. Over the years it was updated and improved with the last one called the SM-4. Sadly, the company is no longer in business. One other commerically made seeing monitor is currently being sold as if July, 2026. This is by Alcor Systems and is the Cyclope and micro-CYCLOPE. Both the SBIG and Alcor Systems above use the Single Image Motion Monitor (SIMM) method for measuring seeing conditions.

I ended up building my own seeing monitor using the SIMM method. It is inspired by the design of the SBIG SM-2, especially for the hardware enclosure. A few differences include having a heater rod inside to prevent dew from forming and melt snow. I also but a small finderscope shoe on top to be able to attach a red dot finder to help quickly point the seeing monitor at Polaris. For a camera, I used a QHY5L-II-M camera. For optics, I am currently using a ZWO 30mm f/4 guider scope with a focal length of 120mm. I picked up a nice machined aluminum gear head alt-az mount from Amazon to precisely aim the camera at the NCP. This is attached to a steel fence pole that is bolted to the observatory concrete pad.

The hardware was actually the easy part. The real challenge was designing the software to process the images and calculate the seeing conditions in real-time. There is no commercial or freeware solution that I am aware of. So I set out on building a comprehensive solution from scratch leverage 2+ decades in IT. Along with the main application, I built an ASCOM driver to be able to get the seeing data into popular imaging software like SGP, NINA, Voyager, etc..

Below are the key features of the seeing monitor:

Support QHY, ZWO, Player One, and the SBIG ST-i cameras. (I do have to maintain this as they roll out new SDKs, or add other manufacturers like Player One)
Any focal lens can be used, the tools menu has a setup to configure that.
It auto detects the camera pixel size on connect to help setup for accurate calculations or it can be manually set
Start/End times to be running is either manual or automated, someone can select like nautical or astronomical twilight.
It can adjust the start/end times daily as those change a few minutes each day (so this becomes a start it and forget)
Focus/alignment mode
Alignment can plate solve with ASTAP and overlay a reticle to help get NCP in the center and a "put Polaris here" to make aligning this super easy.
Outputs a log file that is written to with each reading (roughly every minute)
ASCOM driver for above log file to port into SGP/NINA via the ASCOM Observing Conditions Hub

Below are some screenshots of the seeing monitor in action:

Seeing Monitor software main UI — Main UI

Seeing Monitor software focus and alignment mode — Focus/Alighment Mode

I am pretty happy with the results so far. Depending on interest, I may add more features or improve the existing ones. For that matter, I might even make it available for others to use. I am undecided if I would make this an open source project or offer it for sale.

Feel free to reach out if you have any questions or would like to learn more about the seeing monitor. Email me at pmumbower at hotmail dot com