Gradient Path Labeling Method Used to Refine the Solar Corona Differential Rotation Profile

Coronal Bright Points (CBPs) allow researchers to trace the solar differential rotational profile up to almost polar latitudes detecting and tracking them, over a sufficiently long sequence of images. In this work we discuss the suitability of using an automatic image segmentation algorithm, called Gradient Path Labelling (GPL), for CBP detection and tracking. The GPL algorithm was applied to high-resolution images from the AIA instrument onboard the SDO satellite (19.3 nm channel data with a 10 min cadence and from 3 days interval) to detect and locate CBPs. Their heliographical position was then used for tracking them on a sequence of images. Our test results show that this algorithm is a promising tool to obtain more precise measurements of the solar rotational speed and the meridional motions of CBPs. Moreover, we are developing an interactive website, where the SDO images are continuously downloaded and analysed allowing users to explore selected periods for the corresponding solar rotational profile and some other characteristics of CBPs.