Sentinel-1

Sentinel-1

Sentinel-1 is a constellation of two satellites, 1A (launched in 2014) and 1C (launched in 2024), that are designed to orbit 180° apart and image the whole earth every six days. Together they monitor all tectonically and volcanically active areas of the planet, with their data made freely available to the international Earth Observation community. 

The C-band Synthetic Aperture Radar (SAR) provides a reliable, long-term source of data in all weather, day and night. Interferometric SAR (InSAR) takes two SAR observations of the same area, taken from different positions, and provides information about differences in the distance between the satellite and the Earth’s terrain.

More information on InSAR
  • Launch dates: 
    • Sentinel-1A – 03 April 2014
    • Sentinel-1B – 25 April 2016 
    • Sentinel-1C – 5 December 2024 
    • Sentinel-1D – second half of 2025

Over the years, these satellites have provided valuable scientific results – helping us map earthquakes such as in Napa, California (2014) (see video below), Kaikoura, New Zealand (2016), Amatrice, Italy (2016), Türkiye-Syria Earthquakes (2023) and the Myanmar Earthquakes (2025).

We have created and are continuing to develop an automatic processing system to handle the vast quantities of radar data from Sentinel-1. We use the many thousands of images that Sentinel-1 produces every year to map ground movements with extraordinary accuracy, detecting ground movements as small as 1mm/yr between two points separated by as much as 100 km.

Near volcanoes, such changes can suggest activity below the Earth’s surface.  The data also helps us understand more about the outer layer of the Earth.

Importantly, Sentinel-1 helps us to respond in near-real time to eruption and earthquakes across the globe, and provide information on our website as quickly as possible.

COMET Co-Directors Prof. Juliet Biggs and Prof. Tim Wright wrote a commentary on satellite InSAR for the 10 year anniversary of Nature Communications. Read the article: How satellite InSAR has grown from opportunistic science to routine monitoring over the last decade