Yes thanks from the lazybones.
The authors give actually a coarse error assessment, when they write:
"Our present understanding of both the
satellite and in-situ data is insufficient to resolve any inter-satellite bias to a higher
degree of certainty, but we note that an inter-satellite bias of 10cm would result in an
error in volume of ~700 km³, much lessthan the change in volume between the two
Taking into account the mean errors against "in-situ-measurments", namely:
- airborne electromagnetic - (7 cm),
- upward looking sonar - (-8 cm) and
- airborne laser measurement (-5 cm)
leads to a thickness error estimate around 7 cm against those comparison data.
Remains to add the errors of those data sources themselves, which are given as +-10 cm (airborne EM, ULS), while for the airborne laser data, no error margin is given in the Laxon paper. As lazybones I take its error as the same +-10 cm.
AFAIK error margins add like (sigma_1² + sigma_2²)1/2
, that would be then 12,2 cm. If we are more cautious and take +-10 cm as uncertainty for the in-situ-measurement-Cryosat-relation, we arrive at +-14,4 cm.
Under the assumption of homogeneity this yields together with the base area of 7.2 Mio km² a Cryosat volume error margin of +- 880 km³ or, more cautiously, 1040 km³.
Althoug this is the error margin of one value, the errors are probably not uncorrelated. This means, that I wouldn't expect the values jumping wildly over the whole error interval from one point to the next. It is more like a smaller value of point-to-point jumping added to some longer term shift of the curve.