A team of scientists has drawn on SAOCOM data to measure the heights of forests in Argentina, marking the first time that tree canopies have been mapped using the two-satellite constellation.

This breakthrough study – published in IEEE Xplore – highlights the huge potential of SAOCOM for empowering innovative applications of L-band synthetic aperture radar (SAR) data.

The unique constellation is owned by Argentina's space agency (CONAE) and is part of ESA’s Third Party Missions programme. It occupies a sun-synchronous polar orbit and supplies data to support a wide range of applications – from disaster responses to Antarctic science.

Santiago Seppi, study lead author and researcher at CONAE, explains: “L-band satellite systems are valuable for scientists because they can penetrate thick vegetation, soil and other structures, providing information that shorter wavelength SAR satellites cannot deliver – this impressive capability opens up many avenues of research.

“There are only a handful of L-band systems in orbit and, of these, SAOCOM offers the quickest revisit rate and therefore the highest temporal resolution.”

These attributes were crucial in enabling the research team – which also included Carlos López-Martínez of the Polytechnic University of Catalonia and Jacqueline Joseau of Argentina’s National University of Cordoba – to investigate forest heights in Argentina.

As part of the study, a series of SAOCOM fully polarimetric images were acquired over Corrientes, which is one of the country’s main commercial forestry regions. Supplied directly by CONAE, these data had temporal baselines of between 8 and 16 days between each acquisition.

The results of the study were validated using field measurements obtained on the ground by forestry managers, as well as canopy height measurements from the Global Ecosystem Dynamics Investigation mission.

The team employed a multi-baseline polarimetric interferometric SAR (PolInSAR) approach taken from previous research that used multiple radar images with different spatial and temporal baselines to deliver estimates of canopy heights.

A statistical analysis demonstrated the value of this method, by showing that forest height estimates from SAOCOM aligned well with field measurements collected by teams on the ground.

Co-author Carlos López-Martínez summed up the study by saying: “This research provides new insight into SAOCOM’s PolInSAR capabilities for forest height mapping, with potential applications for commercial forestry managers, as well as policymakers and the scientific community.

“Beyond canopy height mapping, SAOCOM can support many other areas of research, thanks to its unique set of capabilities.”

Potential scientific and operational applications of SAOCOM include Earth system science, climate research, calibration and validation campaigns, ice and glacier monitoring, marine applications, and urban planning.

Data users looking to draw on SAOCOM’s capabilities in their research can access data from the constellation on a free basis via an ESA Third Party Mission Announcement of Opportunity, delivered as part of the Promotion of Utilisation and Mission Applications and Science (PUMAS) initiative.

The call is open to scientists working at institutes in ESA member states, as well as cooperating and associate member states. Proposals are also welcomed from joint European and Argentinian research teams that are working on dedicated PUMAS projects.

To respond to the call for ideas, principal investigators must submit a Project Proposal, which will be evaluated by both ESA and CONAE based on its scientific merits and its alignment with the announcement objectives. The Announcement of Opportunity will close on 31 December 2024.

More information on the call can be found on the SAOCOM Announcement of Opportunity webpage.