Sentinel-2 Photoshop Tutorial

This tutorial explains how to process Sentinel-2 satellite data, released by the European Space Agency for free, into natural color images similar to the one below (Figure 1). Beautification is the goal—nature often can use a little help when using satellite images for maps and graphical presentations.

To do this tutorial you will need Adobe Photoshop and Avenza Geographic Imager, a plugin that adds GIS functionality to Photoshop. Trial versions are available for both applications. You should also have intermediate Photoshop skills, a good internet connection, and a computer with plenty of RAM. Step-by-step instructions show how to create images of three very different landscapes. The techniques become more advanced with each image.

Sentinel-2 at a glance

The European Space Agency operates two identical Sentinel-2 satellites, Sentinel-2A and Sentinel-2B.


The launch of Sentinel-2A occurred in 2015, and Sentinel-2B in 2017.


Each Sentinel-2 satellite takes images of the same place on Earth every 10 days. Because of staggered phasing, they take images of the same place every 5 days.


Coverage includes land areas from 56° S to 84° N, coastal waters, all of the Mediterranean, and oceanic islands larger than 100 square kilometers.


The taking of images occurs around 10:30 AM.


Image width = 290 kilometers (180 miles).


Images are georeferenced in the UTM/WGS 84 coordinate system.


Sentinel-2 does not take photographs. The satellite sensors collect data from discrete portions of the electromagnetic spectrum known as bands, which differ by their wavelength. There are 13 bands (Figure 2).


Each data band is a 16-bit greyscale image in JPEG2000 format.


In addition to the raw data bands, downloads include a true-color image at 10, 20, and 60-meter resolution (comprised of bands 4, 3, and 2). The true-color images are georeferenced RGB files at 8-bit color resolution.

Introduction

Figure 1. Sentinel-2 image of Lake Wakatipu and Queenstown, New Zealand.

Figure 2. Sentinel-2 bands.