Swath Processing improvements of CryoSat-2 for the Study of Ice Caps and Mountain Glaciers

Albert Garcia-Mondejar (isardSAT Ltd., United Kingdom)

CoAuthors

Maria Jose Escorihuela (isardSAT Ltd., United Kingdom); Monica Roca (isardSAT Ltd., United Kingdom); Flora Weissgerber (University of Edinburgh, United Kingdom); Noel Gourmelen (University of Edinburgh, United Kingdom)

Event: 2017 Ocean Surface Topography Science Team Meeting

Session: Science IV: 25 years of satellite altimetry for Cryosphere and Hydrology: from experimental to emerging operational applications

Presentation type: Type Oral

Satellite altimetry has been used extensively in the past few decades to observe changes affecting large and remote regions covered by land ice such as the Greenland and Antarctic ice sheets. Glaciers and ice caps have been studied less extensively due to the limitation of altimetry over complex topography. However, their role in current sea-level budgets is significant and is expected to continue over the next century and beyond (Gardner et al., 2011), particularly in the Arctic where mean annual surface temperatures have recently been increasing twice as fast as the global average (Screen and Simmonds, 2010).
Radar altimetry is well suited to monitor elevation changes over land ice due to its all-weather year-round capability of observing ice surfaces. Since 2010, the Synthetic Interferometric Radar Altimeter (SIRAL) on board the European Space Agency (ESA) radar altimetry CryoSat (CS) mission has been collecting ice elevation measurements over glaciers and ice caps. Its Synthetic Aperture Radar Interferometric (SARIn) processing feature reduces the size of the footprint along-track and locates the across-track origin of a surface reflector in the presence of a slope. This offers new perspectives for the measurement of regions marked by complex topography.

More recently, data from the CS-SARIn mode have been used to infer elevation beyond the point of closest approach (POCA) with a novel approach known as “swath processing” (Hawley et al., 2009; Gray et al., 2013; Foresta et al., 2016). Together with a denser ground track interspacing of the CS mission, the swath processing technique provides unprecedented spatial coverage and resolution for space borne altimetry, enabling the study of key processes that underlie current changes of ice caps and glaciers.
In the frame of the CryoSat+ Mountain Glacier project, we use CS swath observations to generate global maps of ice elevation change over ice caps and glaciers.

Here we present the retracking improvements that have been included in the swath processing chain to better assess glaciers and ice caps changes and their contribution to changes in sea level.
 

Oral presentation show times:

RoomStart DateEnd Date
Symphony Ballroom IV Wed, Oct 25 2017,15:00 Wed, Oct 25 2017,15:15
Albert Garcia-Mondejar
isardSAT Ltd.
United Kingdom
albert.garcia@isardsat.co.uk