Evaluating Pointing Strategies for Future Solar Flare Missions

TL;DR

This study evaluates various pointing strategies for solar flare observation missions, analyzing historical data to identify methods that maximize flare detection and inform future mission design.

Contribution

It provides a comparative analysis of different target selection strategies, highlighting the effectiveness of recent flare activity-based methods and their operational trade-offs.

Findings

Recent flare activity-based strategies outperform others in flare detection.

Active region complexity-based methods show a bias towards the western hemisphere.

Increasing the field-of-view size improves flare observation up to the size of an active region.

Abstract

Solar flares are events of intense scientific interest. Although certain solar conditions are known to be associated with flare activity, the exact location and timing of an individual flare on the Sun cannot as yet be predicted with certainty. Missions whose science objectives depend on observing solar flares must often make difficult decisions on where to target their observations if they do not observe the full solar disk. Yet, little analysis exists in the literature which might guide these missions' operations to maximize their opportunities to observe flares. In this study we analyze and simulate the performance of different observation strategies using historical flare and active region data from 2011 to 2014. We test a number of different target selection strategies based on active region complexity and recent flare activity, each of which is examined under a range of operational assumptions. In each case we investigate various metrics such as the number of flares observed, the size of flares observed, and operational considerations such as the number of instrument re-points that are required. Overall, target selection methods based on recent flare activity showed the best overall performance, but required more repointings than other methods. The mission responsiveness to new information is identified as a strong factor determining flare observation performance. It is also shown that target selection methods based on active region complexities show a significant pointing bias towards the western solar hemisphere. The number of flares observed grows quickly with field-of-view size until the approximate size of an active region is reached, but further improvements beyond the active region size are much more incremental. These results provide valuable performance estimates for a future mission focused on solar flares, and inform the requirements that would ensure mission success.