Status
Critical to progress in understanding and modeling ice sheets are a better characterization of what ice sheets are doing at present, how fast they are changing, what are the driving processes controlling these changes, and how we can better represent these processes in numerical models to derive more realistic predictions of the evolution of glaciers and ice sheets in the future. Chief among these measurements, are detailed, enhanced and sustained measurements of ice sheet elevation, at high spatial resolution, with high vertical accuracy, over the entire ice sheets. These measurements provide critical information about long-term ice sheet dynamics (mass balance trends) and short-term variability (precipitation, ablation events, surface lowering of an accelerating glacier, etc.).
Ideally suited to making these measurements is GLISTIN, a Ka-band single pass interferometric synthetic aperture radar (InSAR). Proposed also as a spaceborne mission concept [1], the airborne GLISTIN-A serves as a proof-of-concept demonstration and science sensor. Key features include:
1. The Ka-band center frequency maximizes the single-pass interferometric accuracy (which is proportional to the wavelength), reduces snow penetration (when compared with lower frequencies), and remains relatively impervious to atmospheric attenuation.
2. Imaging capabilities that are important for mapping large areas. Imaging allows features to be tracked with time for estimation of ice motion and reduces data noise when measuring topographic changes over rough surfaces of glaciers and coastal regions of ice sheets.