# How a sunspot number is calculated by an individual observer?

How a sunspot number is calculated by an individual observer?

I would like to learn how to calculate the daily number of sunspots and where to get daily input images of the Sun.

I have read tens of web links and none mentioned or described any algorithm to work for the calculation of the sunspot number.

https://analyzer.depaul.edu/paperplate/Tracking%20Sunspots.htm

What is the number of sunspots in this paper plate drawing?

https://analyzer.depaul.edu/paperplate/images/Sun_trace_Clyde_zoomR.jpg

visited NOAA, NASA, ESA, SILSO

https://www.sidc.be/silso/dayssnplot

and still no hint and how numbering, encoding is assigned to individual sunspots in the paper plate drawing (as above).

• Isnt there a guide for the formula.. k(10 g + s) where g is the number of sunspot regions, s is the number of spots, and k is a variable quantifying observing conditions and observer biases? Nov 1, 2022 at 22:51
• @LifeInTheTrees since s is the number of spots, so how do you calculate that number ? Exactly what I was asking about. Nov 1, 2022 at 23:02
• As far as I know, it’s the number of spots. The same thing as, e.g., the number of slices of pepper on a pizza. I count ≈ 35 in the drawing you link to, although it’s sometimes difficult to distinguish between two spots or a single large one that is “wasp-shaped.” Nov 2, 2022 at 0:22
• @LifeInTheTrees you are right and I am ready to start with morphological analysis of sunspots. In the mean time I have visited 100+ websites STARA Project: STARA theses.gla.ac.uk/3429/1/2012watsonphd.pdf Glasgow Theses Service theses.gla.ac.uk [email protected] Watson, Fraser Thomas (2012) Investigating sunspot and photospheric magnetic field properties using automated solar feature detection. PhD thesis. theses.gla.ac.uk/3429 29. The STARA Sunspot Catalog Fraser Watson National Solar Observatory, Tucson, AZ 85719, USA Nov 3, 2022 at 21:43
• 2. Sunspot Surface Calculation (Case Study on solving complex problems) V. codeproject.com/Articles/812896/… abandoned project since V. left institute I need to contact Chuck Bueter from Paper Plate Backyard Astronomy Project analyzer.depaul.edu/paperplate since his sunspots count is for real analyzer.depaul.edu/paperplate/images/Sun_trace_Clyde_zoomR.jpg He moved from project to project and hope to contact him via Facebook one day. Than I go to Japan: swc.nict.go.jp/en/trend/sunspot.html Nov 3, 2022 at 21:56