Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgments
- Notation
- 1 Electromagnetic concepts useful for radar applications
- 2 Scattering matrix
- 3 Wave, antenna, and radar polarization
- 4 Dual-polarized wave propagation in precipitation media
- 5 Doppler radar signal theory and spectral estimation
- 6 Dual-polarized radar systems and signal processing algorithms
- 7 The polarimetric basis for characterizing precipitation
- 8 Radar rainfall estimation
- Appendices
- References
- Index
6 - Dual-polarized radar systems and signal processing algorithms
Published online by Cambridge University Press: 14 October 2009
- Frontmatter
- Contents
- Preface
- Acknowledgments
- Notation
- 1 Electromagnetic concepts useful for radar applications
- 2 Scattering matrix
- 3 Wave, antenna, and radar polarization
- 4 Dual-polarized wave propagation in precipitation media
- 5 Doppler radar signal theory and spectral estimation
- 6 Dual-polarized radar systems and signal processing algorithms
- 7 The polarimetric basis for characterizing precipitation
- 8 Radar rainfall estimation
- Appendices
- References
- Index
Summary
Dual-polarized radar systems can be configured in different ways depending on the measurement goals and the choice of orthogonal polarization states. From a theoretical perspective, the 3 × 3 covariance matrix (see Section 3.11) forms a complete set, but only a few research meteorological radars exist at the present time that are configured for this measurement. The circularly polarized radars built at the National Research Council of Canada were essentially configured for coherency matrix measurements (see Section 3.9). In the early 1980s, a number of single-polarized research Doppler radars were upgraded for limited dual-polarization measurements in the linear h/v-basis (for measurement of differential reflectivity and differential propagation phase). Because only copolar signals were involved, the system requirements were much less stringent and significant practical results (e.g. rain rate estimation, hail detection) were obtained fairly quickly (Hall et al. 1980; Bringi et al. 1984; Sachidananda and Zrnić 1986). This chapter discusses a number of dual-polarized radar configurations from a systems perspective. Since antenna performance is critical for achieving high accuracy in the measurement of the “weak” cross-polar signal, both antenna performance characteristics and formulation of radar observables in the presence of system polarization errors are treated. Calibration issues relevant to polarization diversity systems are also discussed. A significant portion of this chapter is devoted to estimation of the elements of the covariance matrix from signal samples under three different pulsing schemes. The accuracy of these covariance matrix estimates is also treated in some detail.
- Type
- Chapter
- Information
- Polarimetric Doppler Weather RadarPrinciples and Applications, pp. 294 - 377Publisher: Cambridge University PressPrint publication year: 2001