Elevation
The surveys of Greenland’s ice sheet were conducted with the GLacier and Ice Surface Topography INterferometer (GLISTIN-A), which aims to produce high spatial resolution (25 m), high-precision (< 50 cm) height maps of Greenland’s coastal glaciers, at 10 to12-km wide swaths using Ka-Band (8.4 mm wavelength) single-pass interferometry. By measuring ice surface elevation changes over several years, volume changes of marine terminating glaciers can be inferred. The GLISTIN-A radar is mounted in a pod under a Gulfstream III airplane. Operating at Ka-Band enhances interferometric accuracy, reduces penetration into the top layers of snow and firn and limits signal attenuation in the atmosphere.
The swaths generally cover the lower parts of the glaciers. The near edges of most swaths are set as close as possible to, and just downstream from, glacier fronts. The remainder of the swaths extend up-glacier from the fronts. Most swaths are flown across glacier flow, capturing as many glacier fronts as possible in each single swath. In the cases of a few large glaciers, swaths are flown along glacier flow, again extending from the front upstream towards the interior of the ice sheet.