Polarization Weather Radar Development from 1970–1995: Personal Reflections

Abstract

The modern era of polarimetric radar begins with radiowave propagation research starting in the early 1970s with applications to measurement and modeling of wave attenuation in rain and depolarization due to ice particles along satellite–earth links. While there is a rich history of radar in meteorology after World War II, the impetus provided by radiowave propagation requirements led to high-quality antennas and feeds. Our journey starts by describing the key institutions and personnel responsible for development of weather radar polarimetry. The early period was dominated by circularly polarized radars for propagation research and at S band (frequency near 3 GHz) for hail detection. By the mid to late 70s, a paradigm shift occurred which led to the dominance of linear polarizations with applications to slant path attenuation prediction as well as estimation of rain rates and inferences of precipitation physics. The period from the early 1980s to 1995 can be considered as the “golden” period of rapid research that brought in meteorologists, cloud physicists, and hydrologists. This article describes the evolution of this technology from the vantage point of the authors. Their personal reflections and “behind the scenes” descriptions offer a glimpse into the inner workings at several key institutions which cannot be found elsewhere.

The Use of Weather Radar Data: Possibilities, Challenges and Advanced Applications

“…The history of Weather Radar (abbreviation of RAdio Detecting And Ranging) begins during World War II, when military radar operators noticed extraneous echoes showing up on their display. David Atlas was one of the pioneers of radar meteorology, along with John Stewart Marshall, Walter Palmer and Richard Doviak [5]. After the second world war, John Stewart Marshall and Walter Palmer investigated Z-R relationships in the Stormy Weather Group.…”

“…Hydrometeors from the Greek hýdōr-metéōros, which means literally "water that is high in the sky" represent all phenomena of condensation and precipitation of atmospheric humidity in liquid or solid particles. When the pulses strike an object such as rain, hail, or snow, Rayleigh scattering occurs and part of the energy is reflected back to the radar receiver (Figure 1) [5]. Rayleigh scattering takes place when the wavelengths are greater than the diameters of the hydrometeor particles.…”

Polarimetric Portraits

“…3.3 Weather radar. There have been decades of research and development on polarimetric radar techniques applied to weather radars as reviewed by Bringi and Zrnic, two of the leading pioneers in this field [Bringi and Zrnic, 2019]. That work led to the Doppler upgrade operationalized in the NEXRAD system, based in part on clever use of interleaved H and V transmissions.…”

“…Equation 1 exposes three key principles: (i) a dual-polarized receiving system provides sufficient data to evaluate the Stokes parameters of the observed field; (ii) the resulting Stokes parameters embody a polarimetric portrait of the observed scene if and only if the illuminating EM source is polarimetrically balanced; and (iii) when the illumination source is constrained to provide balanced illumination with only one transmitted polarization, a circularly polarized transmission is the only option that gives rise to the scene's polarimetric portrait. (In particular, any single linearly-polarized transmission, such as the π/4 mode [Souyris et al, 2005] or its equivalent in weather radar the slant mode [Bringi and Zrnic, 2019] do not satisfy that condition.) 4.3.…”

Bibliometric Analysis of Weather Radar Research from 1945 to 2024: Formations, Developments, and Trends

“…Considering the frequent occurrence of catastrophic weather globally, countries worldwide are actively advancing their respective weather radar networks. Presently, weather radar technology is advancing towards multispectrum techniques (acoustic wave-optical wave-L band-X-C-S band-Ka-W band), multiplatform technology (space-ground-air), refined detection (high precision and high spatiotemporal resolution), all-weather process observation technology (clear-sky atmospheric phase, cloud formation phase, precipitation phase, and meteorological disaster phase), and networked collaborative observation technology (multiband multisystem weather radar) [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. Over the past 80 years since the introduction of the first weather radar, scholars from various countries have published tens of thousands of scientific and technological papers in the field of weather radar, making indelible contributions to the rapid development of weather radar technology.…”