Articles | Volume 10, issue 1
The Cryosphere, 10, 121–131, 2016
https://doi.org/10.5194/tc-10-121-2016
The Cryosphere, 10, 121–131, 2016
https://doi.org/10.5194/tc-10-121-2016

Research article 18 Jan 2016

Research article | 18 Jan 2016

Utilisation of CryoSat-2 SAR altimeter in operational ice charting

E. Rinne and M. Similä E. Rinne and M. Similä
  • Finnish Meteorological Institute, Marine Research, P.O. Box 503, 00101 Helsinki, Finland

Abstract. We present methods to utilise CryoSat-2 (CS-2) synthetic aperture radar (SAR) mode data in operational ice charting. We compare CS-2 data qualitatively to SAR mosaics over the Barents and Kara seas. Furthermore, we compare the CS-2 to archived operational ice charts. We present distributions of four CS-2 waveform parameters for different ice types as presented in the ice charts. We go on to present an automatic classification method for CS-2 data which, after training with operational ice charts, is capable of determining open ocean from ice with a hit rate of  >  90 %. The training data are dynamically updated every 5 days using the most recent 15 days of CS-2 data and operative ice charts. This helps the adaption of the classifier to the evolving ice/snow conditions throughout winter. The classifier is also capable of detecting three different ice classes (thin and thick first-year ice as well as old ice) with success rates good enough for the output to be usable to support operational ice charting. Finally, we present a near-real-time CS-2 product just plotting the waveform characteristics and conclude that even such a simple product is usable for some of the needs of ice charting.

Download
Short summary
This paper demonstrates the use of the CryoSat-2 SAR altimeter in operational ice charting. We take CryoSat-2 data and compare them to ice charts over the sea-ice-covered regions in the Barents and Kara seas. We also present an automatic classification method for CryoSat-2 measurements that could be used to support navigation. We conclude that SAR altimeter measurements can be valuable to operational ice charting if other data sources are unavailable.