The Copernicus Polar Ice and Snow Topography Altimeter (CRISTAL) high-priority candidate mission

• Main Authors: M. Kern, R. Cullen, B. Berruti, J. Bouffard, T. Casal, M. R. Drinkwater, A. Gabriele, A. Lecuyot, M. Ludwig, R. Midthassel, I. Navas Traver, T. Parrinello, G. Ressler, E. Andersson, C. Martin-Puig, O. Andersen, A. Bartsch, S. Farrell, S. Fleury, S. Gascoin, A. Guillot, A. Humbert, E. Rinne, A. Shepherd, M. R. van den Broeke, J. Yackel
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-07-01
• Series: The Cryosphere
• Online Access: https://tc.copernicus.org/articles/14/2235/2020/tc-14-2235-2020.pdf

<p>The Copernicus Polar Ice and Snow Topography Altimeter (CRISTAL) mission is one of six high-priority candidate missions (HPCMs) under consideration by the European Commission to enlarge the Copernicus Space Component. Together, the high-priority candidate missions fill gaps in the measurement capability of the existing Copernicus Space Component to address emerging and urgent user requirements in relation to monitoring anthropogenic <span class="inline-formula">CO₂</span> emissions, polar environments, and land surfaces. The ambition is to enlarge the Copernicus Space Component with the high-priority candidate missions in the mid-2020s to provide enhanced continuity of services in synergy with the next generation of the existing Copernicus Sentinel missions. CRISTAL will carry a dual-frequency synthetic-aperture radar altimeter as its primary payload for measuring surface height and a passive microwave radiometer to support atmospheric corrections and surface-type classification. The altimeter will have interferometric capabilities at Ku-band for improved ground resolution and a second (non-interferometric) Ka-band frequency to provide information on snow layer properties. This paper outlines the user consultations that have supported expansion of the Copernicus Space Component to include the high-priority candidate missions, describes the primary and secondary objectives of the CRISTAL mission, identifies the key contributions the CRISTAL mission will make, and presents a concept – as far as it is already defined – for the mission payload.</p>