Relationships between rainfall rate and 35-GHz attenuation and differential attenuation: Modeling the effects of raindrop size distribution, canting, and oscillation

Kültegin Aydin, Scan E.A. Daisley

    Research output: Contribution to journalArticlepeer-review

    15 Scopus citations

    Abstract

    Power law relationships of the form R = aAb are derived, where R is the rainfall rate, and A is the 35-GHz specific attenuation Ah or specific differential attenuation ΔA = Ah - Av, where the subscripts h and v indicate horizontal and vertical polarizations. The effects of raindrop size distribution, canting, and oscillation on these relationships are evaluated quantitatively. The drop size distributions (DSDs) are obtained from ground-based disdrometer measurements from three different geographical locations around the world. The R-Ah relationship is negligibly affected by raindrop canting and oscillation. It is affected to some extent by DSD variations, with less than 15% fractional standard error (FSE) in the estimated rainfall rate RAh. On the other hand, the R-ΔA relationship is most sensitive to raindrop oscillation, up to about 35% difference in RΔA compared to the no-oscillationcase, and the effect of canting is about 9% for a standard deviation of 10° of the polar canting angle compared with no canting. The FSE due to variations in the DSD for R < 5 mm h-1 is greater than 30% and increases with decreasing R. However, for R > 20 mm h-1, the FSE in RΔA is comparable (and even lower for R > 30 mm h-1) to that of RAh. The exceptions to this are rainfall rates with DSDs dominated by smaller raindrops (diameters less than 2.4 mm). It is also emphasized that because oscillation and canting affect ΔA but not Ah, they could be used in combination for determining the presence of drop oscillation and canting and for estimating an effective raindrop shape model (axial ratio versus size).

    Original languageEnglish (US)
    Pages (from-to)2343-2352
    Number of pages10
    JournalIEEE Transactions on Geoscience and Remote Sensing
    Volume40
    Issue number11
    DOIs
    StatePublished - Nov 2002

    All Science Journal Classification (ASJC) codes

    • Electrical and Electronic Engineering
    • Earth and Planetary Sciences(all)

    Fingerprint Dive into the research topics of 'Relationships between rainfall rate and 35-GHz attenuation and differential attenuation: Modeling the effects of raindrop size distribution, canting, and oscillation'. Together they form a unique fingerprint.

    Cite this