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You searched for +publisher:"University of Oklahoma" +contributor:("Salazar-Cerreno, Jorge"). Showing records 1 – 2 of 2 total matches.

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University of Oklahoma

1. Schvartzman, David. Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar.

Degree: PhD, 2020, University of Oklahoma

The Weather Surveillance Radar 1988 Doppler (WSR-88D) network has been operational for over 30 years and is still the primary observational instrument employed by the National Weather Service (NWS) forecasters to support their critical mission of issuing severe weather warnings and forecasts in the United States. Nevertheless, the WSR-88Ds have exceeded their engineering design lifespan and are projected to reach the end of operational lifetime by 2040. Technological limitations may prevent the WSR-88D to meet demanding functional requirements for future observational needs. The National Oceanic and Atmospheric Administration (NOAA) has started considering radar systems with advanced capabilities for the eventual replacement of the WSR-88D. Unique and flexible capabilities offered by Phased Array Radar (PAR) technology support the required enhanced weather surveillance strategies that are envisioned to improve the weather radar products, making PAR technology an attractive candidate for the next generation of weather radars. If PAR technology is to replace the operational WSR-88D, important decisions must be made regarding the architecture that will be needed to meet the functional requirements. A four-faced planar PAR (4F-PAR) is expected to achieve the requirements set forth by NOAA and the NWS, but deploying and maintaining an operational network of these radars across the U.S. will likely be unaffordable. A more affordable alternative radar system is based on a single-face Rotating PAR (RPAR) architecture, which is capable of exceeding the functionality provided by the WSR-88D network. This dissertation is focused on exploring advanced RPAR scanning techniques in support of meeting future radar functional requirements. A survey of unique RPAR capabilities is conducted to determine which ones could be exploited under an RPAR Concept of Operations (CONOPS). Three capabilities are selected for further investigation: beam agility, digital beamforming, and dwell flexibility. The RPARs beam agility is exploited to minimize the beam smearing that results from the rotation of the antenna system over the collection of samples in the coherent processing interval. The use of digital beamforming is investigated as a possible way to reduce the scan time and/or the variance of estimates. The RPAR's dwell flexibility capability is explored as a possible way to tailor the scan to meteorological observations with the goal of improving data quality. Three advanced RPAR scanning techniques are developed exploiting these capabilities, and their performance in support of meeting the radar functional requirements is quantified. The proposed techniques are implemented on the Advanced Technology Demonstrator (ATD), a dual-polarization RPAR system at the National Severe Storms Laboratory (NSSL) in Norman, OK. Data collection experiments are conducted with the ATD to demonstrate the performance of the proposed techniques for dual-polarization observations. Results are verified by quantitatively comparing fields of radar-variable… Advisors/Committee Members: Yu, Tian-You (advisor), Torres, Sebastian (committee member), Yeary, Mark (committee member), Salazar-Cerreno, Jorge (committee member), Wang, Ying (committee member).

Subjects/Keywords: Weather Radar; Polarimetric Phased Array Radar; Signal Processing; Concept of Operations; Digital Beamdorming

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Schvartzman, D. (2020). Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/326580

Chicago Manual of Style (16th Edition):

Schvartzman, David. “Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed March 05, 2021. http://hdl.handle.net/11244/326580.

MLA Handbook (7th Edition):

Schvartzman, David. “Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar.” 2020. Web. 05 Mar 2021.

Vancouver:

Schvartzman D. Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/11244/326580.

Council of Science Editors:

Schvartzman D. Signal Processing Techniques and Concept of Operations for Polarimetric Rotating Phased Array Radar. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/326580


University of Oklahoma

2. Umeyama Matsumoto, Arturo. Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars.

Degree: PhD, 2020, University of Oklahoma

The use of phased array radars for the US weather radar network (NEXRAD) has been proposed in lieu of the current mechanically steered dish-based systems, owing to its many attractive features, e.g., electronic steering and fast update rates, and others. Scatterer identification (hydrometeors and non-hydrometeors), accurate estimation of rainfall rates, and determination of propagation effects is possible in weather radars through polarimetry. However, the existence of cross-polarization, and co-polarization mismatch in the H- and V-polarization radiation patterns introduces biases in the polarimetric weather radar products, which can adversely affect the accuracy of the estimates of byproducts, thus imposing strict antenna requirements on the co-polarization mismatch of no greater than 0.1 dB, and cross-polarization levels of no greater than about -45 dB. Since the radiation characteristics of phased arrays are inherently dependent on the scanning direction, it becomes even more challenging to meet these requirements. Furthermore, ensuring that each system in this large network meets the requirements becomes an additional challenge where accurate characterization and calibration will be critical. Clearly, the system and instrumentation used for characterization also need to meet or exceed the system level requirements to provide reliable weather-radar-based estimates. Given that radar and other communications systems require in-situ calibration, it is hypothesized that a UAV-based antenna measurement system is able to replace conventional outdoor ranges in virtue of its low cost and flexibility of operation. The proposed solution is a UAV-based in-situ antenna characterization system with the necessary RF instrumentation to perform accurate measurements of a typical weather radar, along with general guidelines and procedures to ensure optimal results. This solution attempts to provide a portable and cost-effective alternative to conventional outdoor antenna ranges, which can be deployed in multiple sites with few to no modifications. While previous works in the literature have had successful results in the use of UAVs for far-field (FF) antenna measurements in a variety of operating frequencies, no other work has currently shown the RF performance needed to meet the stringent requirements expected in an application such as polarimetric weather radars. It is shown in this work, that the characterization and calibration of real polarimetric weather radar systems is possible to a high degree of accuracy set forth by the most critical requirements, i.e., co-polarization mismatch no greater than 0.1 dB and cross-polarization levels below -45 dB. Advisors/Committee Members: Salazar Cerreno, Jorge (advisor), Fulton, Caleb (committee member), Palmer, Robert (committee member), Cheong, Boon Leng (committee member), Chilson, Phillip (committee member), Moghanloo, Rouzbeh (committee member).

Subjects/Keywords: Engineering, Electronics and Electrical.; Physics, Atmospheric Science.; Remote Sensing.; Engineering, Aerospace.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Umeyama Matsumoto, A. (2020). Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/326678

Chicago Manual of Style (16th Edition):

Umeyama Matsumoto, Arturo. “Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed March 05, 2021. http://hdl.handle.net/11244/326678.

MLA Handbook (7th Edition):

Umeyama Matsumoto, Arturo. “Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars.” 2020. Web. 05 Mar 2021.

Vancouver:

Umeyama Matsumoto A. Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/11244/326678.

Council of Science Editors:

Umeyama Matsumoto A. Unmanned Aerial Vehicle-based Far-Field Antenna Characterization System for Polarimetric Weather Radars. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/326678

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