Training at Digital Earth Africa has moved! Register at to enrol in the revised and updated 6-week training course, now called Intro to Sandbox (EN) and Introduction à la sandbox (FR). Find out more about the move on our blog.

Quiz links are no longer available from this website. Please complete the Intro to Sandbox course on to receive a certificate.

La formation à Digital Earth Africa a déménagé ! Connectez-vous sur pour vous inscrire à la formation révisée et mise à jour, désormais appelée Introduction à la sandbox (FR) et Intro to Sandbox (EN). En savoir plus sur le déménagement en consultant notre blog.

Les liens de quiz ne sont plus disponibles sur ce site Web. Veuillez suivre le cours Introduction à la sandbox sur pour recevoir un certificat.

Session 3: Composites

In this session, we will explore the advantages of having satellite data available over a long period of time. We can fill in missing or bad data from one day with data from another day. This creates a complete image known as a composite. The most scientifically rigorous way of combining data is to use a geomedian.

First, we will introduce composites and geomedians. Then, the exercise will walk through removing cloudy data points from our datasets, and show you how to produce cloud-free geomedian composite images.