CryoSat 2 Radar Altimeter


European Space Agency (ESA)

Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research

Principal contacts

Dr. Stefan Hendricks (

Dr. Robert Ricker (

Dr. Veit Helm (

Data web site

General Web site



CryoSat Radar Altimeter


Arctic Ocean

Time intervals

Nov 2010 - Oct 2018 ( no data from June through September)

Data processing notes

This data provides measurements of sea ice thickness and associated uncertainties from the CryoSat-2 mission. Thickness is derived from Radar Altimeter freeboard measurements. The unified thickness data version is derived from the original monthly average AWI products by creating clusters of 50 km averages from the 25km grid of the AWI source product. Mean ice thickness for each cluster is computed by averaging adjacent grid cells. The input thicknesses are weighted by the random uncertainties provided for each grid cell during averaging (Eq 1). The AWI data sets separates random and systematic uncertainties (see Ricker et al. 2014 for details). Random uncertainties for the unified thickness CDR version of this product are computed from the individual grid cell uncertainties (Eq 2)


EQ 1

EQ 2


Where Tcdr is the CDR cluster average thickness, N the number of grid cells from the AWI product used in cluster (4 or 5), Ti is the sea ice thickness for input grid cell i is the ice thickness uncertainty for the cluster, and the variance of the uncertainty in the AWI input product.

Systematic uncertainties are computed as the mean of the input systematic uncertainties.


V20181120: created from AWI data set downloaded on 2018-11-25. This version uses the AWI version 2.1

Number of samples

170622 clusters from Nov 2010 through Oct 2018


Point data

Gridded Cryosat 2 data from AWI


Ricker, R., S. Hendricks, V. Helm, H. Skourup, and M. Davidson (2014), Sensitivity of CryoSat-2 Arctic sea-ice freeboard and thickness on radar-waveform interpretation, The Cryosphere, 8 (4), 1607-1622, doi:10.5194/tc-8-1607-2014.


Processing of the CryoSat-2 (PARAMETER) is funded by the German Ministry of Economics Affairs and Energy (grant: 50EE1008) and data from DATE to DATE obtained from (grant: REKLIM-2013-04).

Sample Maps of Cluster Locations

Sample Maps of Ice Thickness Clusters derived from AWI-CryoSat for April 2015 a) and Oct 2015 b).


Box Plots

Box Plot of Ice Thickness distribution by month for all clusters. Box provides the Median and 25% and 75% interquartile range. Whiskers show the1.5 interquartile range and outliers beyond that are shown with black symbols