ApL D2p radar Altimeter over Land and sea ice

easuring changes in the cryosphere from satellite-based altimeters has and will continue to provide data that are essential to our understanding of the long-term trends of the earth’s ice cover. over the past years, ApL has played a major role in airborne field activities observing continental ice sheets, outlet glaciers, and sea ice using the delayDoppler phase-monopulse (D2p) airborne radar altimeter, designed and built by staff at ApL as part of the nAsA instrument incubator program. The D2p altimeter has been deployed during field campaigns in both the Arctic (2002 and 2003) and Antarctic (2003 and 2004). During these airborne deployments, radar data were collected along with simultaneous and coincidental laser altimeter measurements. The resulting comparisons show that the two altimeters respond quite differently to the various cryospheric geologies. This article briefly reviews the D2p system and compares radar and laser altimeter data selected from the campaigns.