# Chinese Sunspot Drawing and Its Digitization-(I) Parameter Archives

## TL;DR

This paper presents a comprehensive digitized dataset of Chinese historical sunspot drawings from 1925 to 2015, filling a long-term observational gap and supporting solar activity research.

## Contribution

It is the first systematic digitization project of Chinese sunspot drawings, creating a valuable long-term data archive for solar physics research.

## Key findings

- Constructed a dataset with scanned images and parameters from 1925 to 2015.
- Filled a 90-year observational gap in Chinese solar data.
- Provided detailed information for long-term solar cycle studies.

## Abstract

Based on the Chinese historical sunspots drawings, a data set consisting of the scanned images and all their digitized parameters from 1925 to 2015 have been constructed. In this paper, we briefly describe the developmental history of sunspots drawings in China. This paper describes the preliminary processing processes that strat from the initial data (inputing to the scanning equipment) to the parameters extraction, and finally summarizes the general features of this dataset. It is the first systematic project in Chinese solar-physics community that the historical observation of sunspots drawings were digitized. Our data set fills in an almost ninety years historical gap, which span 60 degrees from east to west and 50 degrees from north to south and have no continuous and detailed digital sunspot observation information. As a complementary to other sunspots observation in the world, our dataset provided abundant information to the long term solar cycles solar activity research.