Comparison of Spatial Resolutions in Satellite Images

I wanted to better understand what is the difference between different spatial resolutions in satellite images. What can you really see in a 10 meter resolution image? What is the actual difference between 20 meter and 100 meter resolution? To get an answer for these questions I carried out a simple test.

How I did it

I used Sentinel-2A true color images (TCI) as baseline. These Sentinel-2 images have 10 meter resolution. Of course there are commercial satellites with better than 1 meter resolution but I wanted to concentrate on satellite data that is openly available for everyone. Four different 8 km x 8 km test scenes were tested:

  • downtown San Francisco, California
  • center pivot irrigation systems in Sahara desert
  • Brahmaputra River in India
  • Pukaki Lake in New Zealand

I downloaded the data from Amazon’s Sentinel-2 service. The coarser resolution images were constructed by downscaling the original 10 m x 10 m image and sharpening the resulting image a little bit. This is not exactly the same thing as taking images with instruments having different spatial resolutions but should be good enough to get an idea how different resolutions look like (also different interpolations etc. affect the results…).

Images with the following resolutions were constructed:

  • 10 m (original image used here): e.g. Sentinel-2 red, green, blue bands
  • 15 m: e.g. Landsat 7 & 8 panchromatic band
  • 20 m: e.g. Sentinel-2 bands 5, 6, 7, 8a, 11, and 12
  • 30 m: e.g. Landsat 4–5 TM bands (excl. thermal)
  • 60 m: e.g. Sentinel-2 bands 1, 9, and 10, Landsat 1–5
  • 100 m: e.g. Landsat 8 Thermal infrared bands
  • 120 m: e.g. Landsat 4–5 thermal band
  • 250 m: e.g. MODIS bands 1 and 2

The script for reproducing the images can be found below.

Test scene: San Francisco (8 km x 8 km)

San Francisco 10 m resolution
San Francisco 15 m resolution
San Francisco 30 m resolution
San Francisco 60 m resolution
San Francisco 100 m resolution
San Francisco 120 m resolution
San Francisco 250 m resolution

Test scene: Center pivot irrigation systems in Sahara desert (8 km x 8 km)

Center pivot irrigation systems 10 m resolution
Center pivot irrigation systems 15 m resolution
Center pivot irrigation systems 20 m resolution
Center pivot irrigation systems 30 m resolution
Center pivot irrigation systems 60 m resolution
Center pivot irrigation systems 100 m resolution
Center pivot irrigation systems 120 m resolution
Center pivot irrigation systems 250 m resolution

Test scene: Brahmaputra river, India (8 km x 8 km)

Brahmaputra river 10 m resolution
Brahmaputra river 15 m resolution
Brahmaputra river 20 m resolution
Brahmaputra river 30 m resolution
Brahmaputra river 60 m resolution
Brahmaputra river 100 m resolution
Brahmaputra river 120 m resolution
Brahmaputra river 250 m resolution

Test scene: Lake Pukaki, New Zealand (8 km x 8 km)

Lake Pukaki 10 m resolution
Lake Pukaki 15 m resolution
Lake Pukaki 20 m resolution
Lake Pukaki 30 m resolution
Lake Pukaki 60 m resolution
Lake Pukaki 100 m resolution
Lake Pukaki 120 m resolution
Lake Pukaki 250 m resolution

Hope you liked the images. If you have any questions/comments/ideas, feel free to contact me (for example in Twitter).

All images contain modified Copernicus Sentinel data 2017.

Code used to construct the images: