As a last step for this e-learning course, we will want to have a look at simple linear regressions.
This statistical tool can enable us to have a look at the trends of a variable over time, like for example precipitation, temperature or NDVI-values.

To calculate linear trends, we will need to prepare the imagery and boundary data, create or access dependent and independent variables to analyze, and run a linear fit function. For this example, we will have a look at how to calculate and visualize the NDVI-trend for the region of Homs, Syria, from all available Landsat 8 Tier 1 Surface Reflection Images. We add a Time Band as the independent variable, and use the NDVI values as the dependent variable.