Over the past two and a half decades, the satellite-based Earth observation market has grown significantly. While optical imagery is still a high priority, the importance of Synthetic Aperture Radar (SAR) has become undeniably important over the past 15 years – a trend which is based on continuous technology improvements and more vendors rising to the equation.

With our highly precise and very high resolution #TerraSAR-X and #TanDEM-X satellites, Airbus is at the very forefront of this development since 2007. In 2018, our Spanish Partner Satellite #PAZ (Hisdesat) was launched. Together, the three satellites form our #Radar Constellation.

We are excited to launch our “SAR Social Media Tutorial” - a mini-series of social media posts, entirely focused on space borne SAR. It has been created for our (future) SAR users who currently having little to no experience with this incredible technology.

It is an easy to digest introduction and will act as a reference guide, highlighting the basic principles of Radar based remote sensing, supported by some very exiting imagery examples.

With that being said, please enjoy this mini-series, starting with our first Episode on SAR basics.


Unlike any ‘passive’ optical systems, SAR sensors do not require external illumination (sunlight) in order to collect (useful) data. Being a so called ‘active’ system, Radar provides its own energy source to illuminate the area of interest and targets – allowing Radar to acquire data completely independent of daylight or weather conditions.

A Radar remote sensing system is based on three main functionalities:

  1. The Transmission of the Radar microwave signal to the ground in its specific wave length (X-Band in the case of our Radar Constellation)
  2. The Reception a portion of the transmitted energy as backscatter from the ground surface
  3. The Processing of the returned signal into an image, alternatively a tailored monitoring or measurement product, considering signal strength and time delay.

Episode 1 SAR Basics

Key take-away:

Today’s Staring SpotLight image in sub-metre resolution has been acquired over Tórshavn, Faroe Islands, which is considered to be the number one ranked city in the world which receives the least amount of sunlight. As usual, the Radar Constellation image is clear and sharp and unaffected by these conditions.