Build circular graph of GO_LIVE data repository

Connect to the ftp, so see the availability of GO_LIVE data over time in a circular graph plot

The GO_LIVE dataset is a collection of glacier velocity products based upon Landsat8. When less than 50% of the scene is cloud free, an image is used. Hence, the temporal coverage might change. In order to get an overview of the data present in the repository a script is made, to retrieve such data and plot it in on a circular graph. This helps in getting an overview in the spread, for inversion etc.

This version is based upon: https://github.com/paul-kassebaum-mathworks/circularGraph However, in that work the nodes have a regular interval, while the graph shown here follows the timeline.

This graphic is also used in: Altena et al. 2019, Extracting recent short-term glacier velocity evolution over southern Alaska and the Yukon from a large collection of Landsat data, The Cryosphere.