In this session, Timothee Dub (Finnish Institute for Health and Welfare, Finland) & Tom Hengl (OpenGeoHub, Netherlands) discussed the basics of Time Series Analysis, including with panel data. We looked into how to take into account seasonality, how to identify a trend and how to investigate the relationship between two-time series, with a focus on practical tips and R packages. By the end of this lecture, participants are able to analyze surveillance data, identify seasonality and investigate potential trends.