Researchers from the Yunnan Observatories of the Chinese Academy of Sciences and Southwest Forestry University have developed an advanced neural network-based method to improve the compression of spectral data from the New Vacuum Solar Telescope (NVST). Published in Solar Physics, this technique addresses challenges in data storage and transmission for high-resolution solar observations.

The NVST produces vast amounts of spectral data, creating significant storage and transmission burdens. Traditional compression techniques, such as principal component analysis (PCA), achieved modest compression ratios (~30) but often introduced distortions in reconstructed data, limiting their utility.

To overcome these limitations, the researchers implemented a deep learning approach using a Convolutional Variational Autoencoder (VAE) for compressing Ca II (8542 Å) spectral data. Their method achieves a compression ratio of up to 107 while preserving data integrity. Crucially, the decompressed data maintains errors within the inherent noise level of the original observations, ensuring scientific reliability. At the highest compression ratio, Doppler velocity errors remain below 5 km/s—a threshold critical for accurate solar physics analysis.

This breakthrough enables more efficient NVST data transmission and sharing while providing a scalable solution for other solar observatories facing similar challenges. Enhanced data compression facilitates broader scientific collaboration and reduces infrastructure constraints.

The study was supported by the National Natural Science Foundation of China, Yunnan Fundamental Research Projects, and additional funding sources.