The principle study sites selected for this project were the Lake Vostok, Dome C and Spirit and sites in East Antarctica (Figure 1), and the Russell Glacier site on Greenland’s western margin (Figure 2). The choice of these sites, as set out in the PVP, was governed by the following criteria:
- The availability of CryoSat-2 SAR acquisitions over land ice.
- The availability of high quality reference data for product validation.
- The study requirements to include sites in both Greenland and Antarctica.
|Figure 1||Figure 2|
The four sites each offer specific characteristics that are beneficial to the aims of the SPICE study. Both Vostok and Dome C are located within the East Antarctic interior (Figure 1) and are characterised by relatively simple topography, low accumulation rates and an absence of surface melting. They therefore allow an evaluation of SPICE products in regions representative of a large part of the Antarctic interior region. The remaining Antarctic site, Spirit, lies in a region of steeper ice sheet topography. The dedicated SAR acquisitions across this site in 2014 provided the opportunity to assess the merits of different SAR processing methodologies in a region representative of the ice sheet margins. These areas are particularly important because they tend to exhibit the greatest changes in ice mass, yet their more complex terrain remains a challenge for conventional radar altimeters.
The final site, Russell Glacier in Western Greenland (Figure 2), lies predominantly within the ablation zone of the ice sheet. It therefore experiences a range of atmospheric and snowpack conditions, including periods of surface melt and bare ice. As such it has enabled us to evaluate SAR performance in a region that is challenging for radar altimeters because of the significant changes in the scattering properties of the ice surface. Lying within the SARIn mode mask, and without dedicated SAR acquisitions, it has however been necessary to undertake the exploratory reprocessing of SARIn FBR to pLRM and pSAR L2 products.