Design, Integration, and Miniaturization of a Multichannel Ultra-Wideband Snow Radar Receiver and Passive Microwave Components

• Main Author: McDaniel, Jay William
• Other Authors: Leuschen, Carl, Yan, Jie-Bang (Stephen), Gogineni, Sivaprasad
• Format: Thesis
• Language: English
• Published: University of Kansas 2015
• Subjects: Electrical engineering; Remote sensing; Electromagnetics; FMCW Radar; Suspended Substrate Stripline (SSS); Ultra-Wideband (UWB); UWB Filter Design; Center for Remote Sensing of Ice Sheets (CReSIS); Sea ice
• Online Access: http://hdl.handle.net/1808/23962; http://dissertations.umi.com/ku:13938

At the Center for Remote Sensing of Ice Sheets (CReSIS), two Ultra-Wideband (UWB) Frequency Modulated Continuous Wave (FMCW) radars are used for remote sensing of snow. The 12-18 GHz Ku-Band Radar altimeters provides high resolution surface elevation measurements, while the 2-8 GHz Snow Radar measures snow thickness over sea ice. In order for the Intergovernmental Panel on Climate Change (IPCC) to continuously develop more accurate models, additional snow characterization over sea ice is needed. Employing a constrained optimization approach, the snow water equivalent (SWE) can be estimated directly from the measured radar backscatter. Using the current Snow Radar depth measurement ability along with modified SWE approximation, remotely sensed snow density data can be gathered over large areas using airborne microwave sensors. These additional snow parameters will allow scientists to more accurately model a given area of snow and its effect on polar climate change. To meet this demand, a new “Airborne” Multi-Channel, Quad-Polarized 2-18GHz Snow Radar has been proposed. With tight size and weight constraints from the airborne platforms deploying with the Navy Research Laboratory (NRL), the need for integrated and miniaturized receivers for cost and size reduction is crucial for future deployments. A set of heterodyne microwave receivers were developed as part of the new 2-18 GHz Snow radar to satisfy the March 2015 NRL deployment. The receivers were designed to enable snow thickness measurements from a survey altitude of 500 feet to 5000 feet while nadir looking, and estimation of SWE from polarimetric backscattered signals at low elevation 30 degree off nadir. The individual receiver has undergone a five times size reduction with respect to initial prototype design, while achieving a sensitivity of -125 dBm on average across the 2-18 GHz bandwidth, enabling measurements with a vertical range resolution of 1.64 cm in snow. The design of a compact enclosure was defined to accommodate up to 18 individual receiver ...