2007/06/19 by Junwei Zhao · 47 citations
Computer Science · Physics and Astronomy · #Astronomy #Computer science #Computer vision #Far side of the Moon #Geology #Helioseismology #Holography #Image (mathematics) #Noise (video) #Optics #Physics #Remote sensing #SIGNAL (programming language) #Solar Radiation and Photovoltaics #Solar and Space Plasma Dynamics #Spurious relationship #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/520837
published in The Astrophysical Journal 664(2), L139-L142 (IOP Publishing) · 13 pages, 5 figures, accepted by ApJ Letters
arxiv created 2007/06/19 · openalex publication_date 2007/07/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is of great importance to monitor large solar active regions on the far side of the Sun for space weather forecasting, in particular, to predict their appearance before they rotate into our view from the solar east limb. Local helioseismology techniques, including helioseismic holography and time distance, have successfully imaged solar far-side active regions. In this Letter, we further explore the possibility of imaging and improving the image quality of solar far-side active regions by use of time-distance helioseismology. In addition to the previously used scheme with four acoustic signal skips, a five-skip scheme is also included in this newly developed technique. The combination of both four- and five-skip far-side images significantly enhances the signal-to-noise ratio in the far-side images and reduces spurious signals. The accuracy of the far-side active region imaging is also assessed using one whole year's solar observation.