On-orbit Performance of the Solar Optical Telescope aboard Hinode

TL;DR

The paper reviews the on-orbit performance of Hinode's Solar Optical Telescope, highlighting its excellent data quality, addressing unexpected issues, and discussing solutions for filter tuning and data analysis improvements.

Contribution

It provides a comprehensive assessment of SOT's on-orbit performance, including novel procedures for filter tuning and data correction methods.

Findings

SOT generally performs excellently with outstanding data quality.

Focus, throughput, and stability issues are mostly mitigated through operational adjustments.

New procedures enable effective tuning of the tunable filter despite air bubbles.

Abstract

On-orbit performance of the Solar Optical Telescope (SOT) aboard Hinode is described with some attentions on its unpredicted aspects. In general, SOT revealed an excellent performance and has been providing outstanding data. Some unexpected features exist, however, in behaviors of the focus position, throughput and structural stability. Most of them are recovered by the daily operation i.e., frequent focus adjustment, careful heater setting and corrections in data analysis. The tunable filter contains air bubbles which degrade the data quality significantly. Schemes for tuning the filter without disturbing the bubbles have been developed and tested, and some useful procedures to obtain Dopplergram and magnetogram are now available. October and March when the orbit of satellite becomes nearly perpendicular to the direction towards the sun provide a favorable condition for continuous runs of the narrow-band filter imager.