Sentinel-1

Sentinel-1, the first Earth Observation mission in ESA’s Copernicus programme, is a constellation of two polar-orbiting, all-weather, day-and-night, synthetic aperture radar (SAR) satellites which are used to monitor ice and oceans as well as changes on land. Sentinel-1A was launched in April 2014, and was joined in orbit by 1B in April 2016.  Together, they monitor the entire planet, passing over the same spot on the ground every 6 days.

CPOM uses Sentinel-1 data to closely monitor the flow of ice out of many large outlet glaciers in Greenland and Antarctica, to track the location of icebergs, and to measure the grounding line position – the boundary between ice shelves floating on the ocean and the grounded ice sheet.

Acquired by Sentinel-1A, this image shows a transect over the northern part of the Antarctica Peninsula. It was acquired in the satellite’s ‘strip map’ mode with a swath width of 80 km and in dual polarisation. The colours indicate how the land, ice and water reflect the radar signal differently.

Credit: ESA

Sentinel-1 data has already provided valuable scientific results, demonstrating for example how quickly Antarctica’s Pine Island glacier is flowing.  The mission, alongside CryoSat, has also been used to measure subtle changes in the elevation and flow of ice shelves that, in turn, reveals how huge canyons are forming underneath:

Greenland’s Zachariae Isstrom glacier (illustrated below) and Thwaites glacier in Antarctica are another two large ice streams which are continuously monitored by Sentinel-1 with results available via the CPOM ice velocity portal, where ice velocity data on six key glaciers is made freely available to the scientific community.

Zachariae Isstrom glacier imaged by Sentinel-1. Credit:ESA