A high-resolution polar ice penetrating radar and experiments in the 28th Chinese National Antarctic Research Expedition

Polar ice penetrating radar is one of the most important devices for polar ice depth sounding. A high resolution ice-penetrating radar is developed to measure the thickness of glacial ice and observe the internal structures and basal conditions of glaciers and ice sheets. With a transmitting frequency at 100-150 MHz, this radar provides a range resolution of about 2m and a penetrating depth about 3000m under polar ice. The radar system uses pulse compression and coherent integration techniques to obtain a high processing gain and improve the signal to noise ratio of the system. A high-speed Direct Digital Synthesizer (DDS) is applied to generate a chirp signal as an input source for the transmitter. The implementation of the digital unit is based on a piece of FPGA chip. To reduce the hardware complexity, intermediate frequency sampling is adopted to digitalize the received analog signal. The measurements were successfully implemented in the 28th Chinese National Antarctic Research Expedition (CHINARE 28, 2011/12) near China Zhongshan Station.