The combination of ERS-1 altimetry and Landsat visible data for mapping of polar ice mass elevation

Surface elevation over polar ice masses is an important glaciological parameter which can be used to help understand the dynamics of ice masses and how they might respond to possible future climate change. It is also a pre-requisite for accurately processing and analysing many remote sensing data sets. The size and inaccessibility of the polar regions makes it impossible to carry out comprehensive field studies to map the surface elevation. Recently SEASAT, GEOSAT and ERS-I altimetry have been used to map the ice sheets of Greenland and Antarctica, demonstrating the role of satellite remote sensing for mapping the polar regions. However there are problems with these data sets: over steep slopes the altimetric systems are unable to maintain lock resulting in the loss of data and the poor across track resolution limits the potential size of the area to be mapped. The authors investigate the use of Landsat/MSS data to model surface elevation and verify the model using 'ground truth' data. The ability of the ERS-I altimeter to map the relatively small ice cap of Austfonna, Svalbard (11262 km/sup 2/) is also investigated and modelled elevation heights are combined with the altimeter data to produce a new map of surface elevation.