ESA Sentinel 1A: First radar vision for Copernicus

Brussels from Sentinel-1A. Credit: ESA

Launched on 3 April, ESA's Sentinel-1A satellite has already delivered its first radar images of Earth.

They offer a tantalising glimpse of the kind of operational imagery that this new mission will provide for Europe's ambitious Copernicus environmental monitoring programme.

Rather aptly, the first image shows Brussels in Belgium, the seat of the European Commission.

The European Commission leads the Copernicus programme and coordinates the broad range of services to improve the management of the environment and to safeguard everyday lives.

ESA is responsible for developing the family of Sentinel satellites and for ensuring that the stream of data are available for these services.

This first image of Belgium was captured on 12 April, just one day after the satellite was put into its operational attitude, and demonstrates the potential of Sentinel-1A's radar vision.

Since it was launched from Europe's Spaceport in French Guiana, Sentinel-1A has undertaken a complicated routine to deploy its 12-m long radar and two 10-m long solar wings, as well as passing a series of initial instrument checks.

The satellite is not yet in its operational orbit, nor is it calibrated for supplying true data. These tasks will be carried out during the commissioning phase, which will take about three months to complete.

This preliminary set of images simply offer a taster of what's to come.

One of the images acquired on the same day focuses on Pine Island Glacier in Antarctica. 

This glacier is in a state of 'irreversible retreat' so it is important to keep a very close eye on glaciers such as these as they lose ice to the ocean.

Another shows a transect over the northern part of the Antarctica Peninsula.

As well as monitoring glaciers, Sentinel-1A is poised to generate timely maps of sea-ice conditions, particularly for the increasingly busy Arctic waters.

Images from its advanced radar can be used to distinguish clearly between the thinner more navigable first-year ice and the hazardous, much thicker multiyear ice to help assure safe year-round navigation in polar waters.

As these first images show, Sentinel-1A is already demonstrating the vital role it will play in the largest civil Earth observation programme ever conceived.

ESA Sentinel-1A: Preparation for radar vision

This ‘interferogram’ shows Petermann Glacier grinding towards the sea along the northwestern coast of Greenland. 

Two Radarsat-2 TOPS images acquired 24 days apart were used to generate it. 

Radarsat-2 was programmed specially by MDA to work in an experimental imaging mode called Terrain Observation by Progressive Scans (TOPS) in azimuth to match the way ESA’s Sentinel-1 will image Earth. 

Credit: ESA/MDA

Sentinel-1A, Europe's first satellite for Copernicus, is almost ready for launch on 3 April. Meanwhile, ESA is showing how its advanced radar will map ice, monitor subsidence and much more.

Marking a new era in Earth observation focusing on operational applications, Sentinel-1A is set to deliver timely imagery for numerous Copernicus services.

Carrying an advanced radar, it will scan Earth's surface no matter what the weather and regardless of whether it is day or night.

In crisis situations, it will be used for rapid response to disasters such as floods and earthquakes. Its radar will routinely monitor shipping zones, map sea ice and provide information on winds and waves for marine traffic, track changes in the way land is being used, and monitor subsidence.

It will also track how glaciers move, as shown in the image above of Petermann Glacier in northwest Greenland.

So that users are fully prepared for the images Sentinel-1A delivers, Canada's Radarsat-2 was recently programmed by MacDonald, Dettweiler & Associates to scan Earth's surface using the same novel 'interferometric' wide-swath mode technique as Sentinel-1.

Consequently, a suite of images was acquired over various sites.



Carrying an advanced radar, Sentinel-1A can image Earth’s surface no matter what the weather and regardless of whether it is day or night. 

This makes it an ideal mission for monitoring the polar regions, which are shrouded in darkness for months at a time. 

As well as providing information on changing ice cover and glacial flows, Sentinel-1 will provide imagery of sea-ice for maritime navigation in polar waters. 

Sentinel-1A will also be used to track changes in the way land is used and to monitor ground movement. 

Moreover, this new mission is designed specifically for fast response to aid emergencies and disasters such as flooding and earthquakes. 

Sentinel-1A, the first in the family of satellites for Europe’s environmental monitoring Copernicus programme, marks a new era in Earth observation, focusing on operational missions to support users for decades to come. 

Credit: ESA/ATG medialab

As the most realistic Sentinel-1A-like images to date, they show the performance and suitability of the new mission for classifying different types of sea ice, detecting ships and monitoring oil platforms.

They also included image pairs to show changes in glaciers such as Petermann, and a 'stack' of 11 images to map surface subsidence in Mexico City.

The image of Petermann Glacier was derived from two images taken 24 days apart. It shows some stationary and slowly moving features, as well as some large areas of much faster-moving ice.

The pattern's fringes are widely spaced in the stationary areas and closer together in the centre of the glacier where the ice is moving much faster.

The wealth of data available through ESA's Earth observation campaign data website is helping to pave the way for users to get the maximum out of the upcoming mission.

The Sentinel-1mission comprises two identical satellites for optimal global coverage and data delivery.

Sentinel-1B will join Sentinel-1A in orbit next year.