1. Ventures Proposal Science Objectives and Requirements

2. Science Goals Obtain 3-dimensional imagery of ice sheet surface and base to: – Refine estimates of ice sheet mass balance by comparing flux gate methods and repeat lidar measurements – Improve dynamical ice sheet models to predict future behavior of the ice sheets and their contribution to sea level.

3. Physical Properties of the Ice Sheets RAMP coastline, flow lines and surface velocities (Jezek, 2008) GISMO flight lines, flow lines, coastline (Jezek, Joughin, Csatho)

4. Science Objectives By increasing level of complexity – Phase 1: Obtain 3-dimensional imagery of ice sheet surface and base for selected glacier basins in Greenland and Antarctica (e.g. Peterman Glacier, Byrd Glacier) – Phase 2: Obtain 3-dimensional imagery of ice sheet surface and base for a 100 km strip extending about the ice sheets interior from the grounding line. Supplement with selected sites of interest (e.g. Lake Vostok) – Post Ventures: Obtain complete, 3-dimensional imagery of ice sheet surface, internal layers, and base.

5. Science Requirements 5 m vertical ice sheet surface height accuracy – radar 10 cm vertical ice sheet surface height accuracy - laser 20 m vertical ice sheet base height accuracy 20 m vertical accuracy on radar internal layers 25 m geolocation accuracy (WGS 84/polar sterographic projections) Relative radiometric accuracy sufficient to discriminate rock from water 50 m pixels 10 km swath primary goal, nadir profile of basal topography over most complex glacial regimes 5-10 year repeat of integrated measurements Data products to be integrable with DESDYNI surface velocities and ICEsat surface topography