The Importance of Accurately Measuring the Range Correlation for Range-Oversampling Processing

Sebastián M. Torres Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, and NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma

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Christopher D. Curtis Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, and NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma

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Abstract

A fundamental assumption for the application of range-oversampling techniques is that the correlation of oversampled signals in range is accurately known. In this paper, a theoretical framework is derived to quantify the effects of inaccurate range correlation measurements on the performance of such techniques, which include digital matched filtering and those based on decorrelation (whitening) transformations. It is demonstrated that significant reflectivity biases and increased variance of estimates can occur if the range correlation is not accurately measured. Simulations and real data are used to validate the theoretical results and to illustrate the detrimental effects of mismeasurements. Results from this work underline the need for reliable calibration in the context of range-oversampling processing, and they can be used to establish appropriate accuracy requirements for the measurement of the range correlation on modern weather radars.

Corresponding author address: Sebastian Torres, National Weather Center, 120 David L. Boren Blvd., Norman, OK 73072. E-mail: sebastian.torres@noaa.gov

Abstract

A fundamental assumption for the application of range-oversampling techniques is that the correlation of oversampled signals in range is accurately known. In this paper, a theoretical framework is derived to quantify the effects of inaccurate range correlation measurements on the performance of such techniques, which include digital matched filtering and those based on decorrelation (whitening) transformations. It is demonstrated that significant reflectivity biases and increased variance of estimates can occur if the range correlation is not accurately measured. Simulations and real data are used to validate the theoretical results and to illustrate the detrimental effects of mismeasurements. Results from this work underline the need for reliable calibration in the context of range-oversampling processing, and they can be used to establish appropriate accuracy requirements for the measurement of the range correlation on modern weather radars.

Corresponding author address: Sebastian Torres, National Weather Center, 120 David L. Boren Blvd., Norman, OK 73072. E-mail: sebastian.torres@noaa.gov
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