Development, Integration, and Deployment of an Advanced Radar Depth Sounder for Ice Imaging Onboard the NASA Gulfstream V Aircraft

This paper presents the adaptation and integration of the University of Kansas' Multichannel Coherent Radar Depth Sounder (MCoRDS) for operation onboard the NASA Gulfstream V aircraft during the closing phase of Operation IceBridge (OIB). The mission objectives included measuring ice sheet thickness in Antarctica, imaging deep internal layers, and mapping glaciers along their flowline. First, we discuss the development of a custom four-element antenna array designed under tight structural constraints to support operation over the 236 – 254 MHz frequency range. We document the development of the antenna elements, feed structure, fiberglass composite fairing, and ground plane considerations for integration onto a carbon fiber composite panel. We also provide a summary of modifications to the radar electronics to support operation over the above band. This includes the implementation of a compact multi-channel radar transmitter capable of a maximum peak transmit power of 1 kW per channel. Next, we discuss results from test flights over the Gulf of Mexico, conducted to assess the impulse response and sensitivity of the system and in-flight radiation pattern of the realized antenna array. Lastly, we discuss how the radar was used to survey the Antarctic coast in the Western Pacific Ocean Sector approximately between Davis Sea and Dumont d'Urville Sea. We completed nineteen flights within one month, during which we collected a total of 5.5 terabytes of raw data covering ∼21,000 kilometers. The radar measured a maximum ice thickness of 4.484 km and mapped ice stratigraphy with a vertical resolution smaller than 10 m. Overall, the radar development, integration, and performance are satisfactory, and the field campaign is a success.