AlTiS (Altimetry Time Series) is a software to visualize and process radar altimetry data. It was developed to analyse radar altimetry data over small areas like river, lakes and wetlands, located in the altimetry groundtracks. Its major goal is the creation of time-series of water levels from the height derive from the altimeter measurement but it can also be used to generate time series of any altimetry-based parameters (e.g., corrections applied to the range, backscattering...