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Remote Sensing of Sea Ice with Wideband Microwave Radiometry

Demir, Oguz
http://orcid.org/0000-0002-4066-8481
http://rave.ohiolink.edu/etdc/view?acc_num=osu1638016458228432

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
Sea ice is one of the most important components of Earth’s cryosphere that regulates heat flow between the ocean and atmosphere, impacts water cycles and oceanic currents due to salt transport during the melt and freeze seasons, provides a natural habitat for many life forms, and affects global transportation. Remote sensing of sea ice has become more important than ever given the substantial reduction in sea ice extent in the Arctic in recent decades. A major advantage of remote sensing for sea ice studies is the continuous monitoring available from space that eliminates the need for expensive and difficult in-situ measurements. Although satellite-borne passive microwave radiometer observations of sea ice have been performed since the 1970s, significant challenges remain. Radiometer measurements at frequencies greater than approximately 19 GHz can detect sea ice concentration and extent but are impacted by clouds. L-band radiometers operating at 1.4 GHz have been shown to successfully estimate sea ice thicknesses up to ~1.5 m; however, thickness sensing performance is limited by the penetration depth in sea ice at this signal frequency. Radiometers operating at lower frequencies have not been used on satellites to date due to the strong man-made radio frequency interference (RFI) present at frequencies less than 1.4 GHz. The Ultra-Wideband Software-defined Microwave Radiometer (UWBRAD) was developed at The Ohio State University to observe thermal emissions in the presence of RFI. The instrument performs RFI detection and mitigation algorithms at multiple frequency channels from 0.5 – 2.0 GHz. As a result, UWBRAD is capable of retrieving sea ice thickness for ice thicknesses greater than 1.5 m due to its lower operating frequencies. In addition, the measurement of sea ice thermal emissions over the 0.5-2 GHz spectrum reveals additional information on ice characteristics and can allow the simultaneous retrieval of sea ice thickness and salinity. This dissertation examines the remote sensing of sea ice through wideband microwave radiometry. Sea ice thermal emissions are modeled for UWBRAD’s 0.5-2 GHz frequency spectrum and compared with measurements from validation campaigns. A retrieval process is also described to characterize ice thickness and salinity. Results from the two successful campaigns in which the instrument was operated in Greenland and in the Arctic are demonstrated. In addition, wideband retrieval performance is further investigated to explore the effect of available ancillary data, and Arctic scale retrieval simulations are described that provide additional insights to guide future wideband radiometer remote sensing missions.
Joel T. Johnson (Advisor)
Robert Lee (Committee Member)
Caglar Yardim (Committee Member)
Kenneth C. Jezek (Committee Member)
134 p.
Electrical Engineering; Electromagnetics; Remote Sensing
Remote Sensing; Microwave Radiometry; Wideband Radiometer; UWBRAD; Cryosphere; Sea Ice

Recommended Citations

Citations

  • Demir, O. (2021). Remote Sensing of Sea Ice with Wideband Microwave Radiometry [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1638016458228432

    APA Style (7th edition)

  • Demir, Oguz. Remote Sensing of Sea Ice with Wideband Microwave Radiometry. 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1638016458228432.

    MLA Style (8th edition)

  • Demir, Oguz. "Remote Sensing of Sea Ice with Wideband Microwave Radiometry." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1638016458228432

    Chicago Manual of Style (17th edition)

osu1638016458228432
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This open access ETD is published by The Ohio State University and OhioLINK.