DEVELOPMENT OF AN ICE-PENETRATING SOFTWARE-DEFINED RADAR USING THE UNIVERSAL SOFTWARE RADIO PERIPHERAL PLATFORM

Open Access
Author:
Liu, Peng
Graduate Program:
Electrical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 10, 2014
Committee Members:
  • Sven G Bilen, Thesis Advisor
  • Julio Urbina, Thesis Advisor
  • Sridhar Anandakrishnan, Thesis Advisor
Keywords:
  • Ice-penetrating Radar
  • Software-defined Radio
  • USRP
Abstract:
An ice-penetrating software-defined radar has been developed using the Universal Software Radio Peripheral (USRP) that generates chirp signals. Called the USRP-based Ice Radar, the initial design goal was to create a portable, compact radar that is adaptable to future requirements using software-defined-radio techniques. The USRP-based Ice Radar will be used in polar glacier research to determine the depth of ice sheets up to 3 km. This version of the Ice Radar is built on previous versions that were hardware-based and PXI-based. The systems functions by outputting a 20-W in-phase/quadrature chirp from a log-periodic antenna and receiving reflections with a second antenna of the same type. One channel has been established with a bandwidth of 5 MHz. The RF front-end paths have been designed to transmit and receive signals in the proper frequency range and includes a glacier/calibrate mode selection switch and blanking switch modules. An external FPGA has been implemented to generate the blanking switch signal, glacier/calibrate selection, 10-MHz reference clock, and a 500-Hz trigger signal. LabVIEW is used to generate the original chirp signal and to communicate with both the USRP and external FPGA. Simulations were performed in LabVIEW to verify the function of the matched filter and SystemVUE was used to calculate gains in the transmission and receiving paths, and the losses due to the glacier and reflection from bedrock. Network and spectrum analyzers were used to verify the functions of transmitter and receiver paths in the frequency domain. The USRP-based Ice Radar is demonstrated to meet the design goals set out for it.