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Signal Processing

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University of Massachusetts Amherst

Radar

Articles 1 - 9 of 9

Full-Text Articles in Electrical and Computer Engineering

Correcting For Terrain Interference, Attenuation, And System Bias For A Dual Polarimetric, X-Band Radar, Casey Wolsieffer Apr 2021

Correcting For Terrain Interference, Attenuation, And System Bias For A Dual Polarimetric, X-Band Radar, Casey Wolsieffer

Masters Theses

This thesis outlines the procedure and theory used to calibrate the UMass eXperimental X-band Radar (UMAXX) for the purpose of monitoring meteorological events in the Pioneer Valley region. Due to the complex topography of the area, lower tilt angles are subject to partial or full beam blockage as well as ground clutter observed through the main beam or sidelobes. Additionally, there are biases internal and external to the system that impact the reflectivity and differential reflectivity measurements. These biases and corrections are addressed in this work. As the radar has been operational since September of 2018, there is ample data …


The Umass Experimental X-Band Radar (Umaxx): An Upgrade Of The Casa Ma-1 To Support Cross-Polarization Measurements, Jezabel Vilardell Sanchez Aug 2019

The Umass Experimental X-Band Radar (Umaxx): An Upgrade Of The Casa Ma-1 To Support Cross-Polarization Measurements, Jezabel Vilardell Sanchez

Masters Theses

Ground-based radars are instruments commonly used to surveil the precipitation climate of the surrounding areas. Weather events are characterized by collecting backscatter data and analyzing computed products such as the Reflectivity Factor, the Doppler Velocity, the Spectrum Width, the Differential Reflectivity, the Co-polar Correlation Coefficient and the Differential Propagation Phase. The ability of the radar to transmit different polarization waves, such as horizontal and vertical polarization, allow for further analysis of the weather given the capability to perform co-polar and cross-polar measurements. The Linear Depolarization Ratio is another computed product based on the difference in power between the co-polarized and …


Insar Simulations For Swot And Dual Frequency Processing For Topographic Measurements, Gerard Masalias Huguet Mar 2019

Insar Simulations For Swot And Dual Frequency Processing For Topographic Measurements, Gerard Masalias Huguet

Masters Theses

In Earth remote sensing precise characterization of the backscatter coefficient is important to extract valuable information about the observed target. A system that eliminates platform motion during near-nadir airborne observations is presented in this thesis, showing an improvement on the accuracy of measurements for a Ka- band scatterometer previously developed at Microwave Remote Sensing Laboratory (MIRSL). These very same results are used to simulate the reflectivity of such targets as seen from a spaceborne radar and estimate height errors based on mission-specific geometry. Finally, data collected from a dual-frequency airborne interferometer com- prised by the Ka-band system and an S-band …


Kasi: A Ka-Band And S-Band Cross-Track Interferometer, Gerard Ruiz Carregal Mar 2017

Kasi: A Ka-Band And S-Band Cross-Track Interferometer, Gerard Ruiz Carregal

Masters Theses

A dual-frequency system is needed to better understand natural processes that constitute the environment and seasonal cycles of the Earth. A system working at two different wavelengths acquiring data simultaneously will give a valuable dataset since the conditions on the ground will be exactly the same. Hence, elements such as wind, soil moisture or any other changes on the ground will not interfere in the mea- surements. This thesis explains how an S-band radar was built and tested. Moreover, the experiments done with a Ka-band radar used as a scatterometer are explained as well as the data processing and analysis. …


Topography Measurements Using An Airborne Ka-Band Fmcw Interferometric Synthetic Aperture Radar, Kan Fu Mar 2017

Topography Measurements Using An Airborne Ka-Band Fmcw Interferometric Synthetic Aperture Radar, Kan Fu

Doctoral Dissertations

Radar interferometry at millimeter-wave frequencies has the ability of topography measurement of different types of terrain, such as water surfaces and tree canopies. A Ka-band interferometric radar was mounted on an airborne platform, and flown over the Connecticut river region in western Massachusetts near Amherst on June 11, 2012. More than 20 Gigabytes of raw data was recorded. This dissertation outline presents the results of the data processing, which includes (1) the estimation and removal of the embedded high frequency phase error in the raw data; (2) the synthetic aperture processing; (3) the interferometric processing. The digital elevation model (DEM) …


Applications In Low-Power Phased Array Weather Radars, Robert A. Palumbo Jr Mar 2016

Applications In Low-Power Phased Array Weather Radars, Robert A. Palumbo Jr

Doctoral Dissertations

Low-cost X-band radars are an emerging technology that offer significant advantages over traditional systems for weather remote sensing applications. X-band radars provide enhanced angular resolution at a fraction of the aperture size compared to larger, lower frequency systems. Because of their low cost and small form factor, these radars can now be integrated into more research and commercial applications. This work presents research and development activities using a low-cost, X-band (9410 MHz) Phase-Tilt Radar. The phase-tilt design is a novel phased array architecture that allows for rapid electronic scanning in azimuth and mechanical tilting in elevation, as a compromise between …


Integration And Measurements Of A Ka-Band Interferometric Radar In An Airborne Platform, Rockwell B. Schrock Jan 2013

Integration And Measurements Of A Ka-Band Interferometric Radar In An Airborne Platform, Rockwell B. Schrock

Masters Theses 1911 - February 2014

The Topographic Interferometry Mapping Mission (TIMMi) instrument is a unique millimeter wave interferometric radar system operating at 35 GHz (Ka-band). It was constructed in part to advance the technology readiness level of NASA’s Surface Water and Ocean Topography (SWOT) mission, a spaceborne platform that will globally map the altimetry of Earth’s water to gain insight into surface water interactions and dynamics. Previous ground deployments of TIMMi were successful in demonstrating the abilities of the system from a stationary platform. The next logical step was to move TIMMi closer to space by installing it on an airborne platform prove its capability …


Inversion Of Marine Radar Imagery To Surface Realizations And Dual-Polarization Analysis, Brian Paulsen Jan 2011

Inversion Of Marine Radar Imagery To Surface Realizations And Dual-Polarization Analysis, Brian Paulsen

Masters Theses 1911 - February 2014

The ocean influences global weather patterns, stores and transports heat, and supports entire ecosystems. An area of interest is the relationship between the observed backscattered power received by a surface-based marine radar and the ocean surface topography. Current methods for obtaining surface elevation maps involve either in situ devices, which only provide point measurements, or an interferometric radar, which can be costly. During the late 1990's and early 2000's a radar was built at UMass, called the Focused Phased Array Imaging Radar II (FOPAIR II), and deployed at a several locations. A method is discussed to determine a transfer function …


Calibration Of The Umass Advanced Multi-Frequency Radar, Matthew Mclinden Jan 2010

Calibration Of The Umass Advanced Multi-Frequency Radar, Matthew Mclinden

Masters Theses 1911 - February 2014

The Advanced Multi-Frequency Radar is a three-frequency system designed and built by the University of Massachusetts Microwave Remote Sensing Lab (MIRSL). The radar has three frequencies, Ku-band (13.4 GHz), Ka-band (35.6 GHz), and W-band (94.92GHz). The additional information gained from additional frequencies allows the system to be sensitive to a wide range of atmospheric and precipitation particle sizes, while increasing the ability to derive particle microphysics from radar retrievals.

This thesis details the calibration of data from the Canadian CloudSat/CALIPSO Validation Project (C3VP) held during January 2007 in Ontario, Canada. The calibration used internal calibration path data and was confirmed …