### Abstract

We examine backscattering by analyzing large nonspherical particles with flat surfaces for which where the size is much larger than the wavelength, using ray optics and diffraction theory. We show that the backscattering cross section for rectangles can be 1 order of magnitude larger than that for spheres with same geometrical cross sections, depending on the orientation of the particles. Then we show that there is a difficulty in estimating the backscattering cross section for hexagonal columns with the available solutions but that it is possible to estimate the integration of the differential scattering cross section over small solid angles in backward directions. The integral values for hexagonal columns are found to be more than 1 order of magnitude larger than that for spheres with the same volume. As an application, the use of power from hexagonal columns for lidar observations is analyzed. Unlike for spherical particles with their dependence on Z^{-2} (where Z is the distance between the particle and the detector), for nonspherical particles such dependence varies with the particles' nonsphericity, such as shape and orientation: Z^{0} for a hexagonal plate randomly oriented in the horizontal plane; Z^{-1} for a hexagonal column randomly oriented in the horizontal plane.

Original language | English |
---|---|

Pages (from-to) | 6121-6129 |

Number of pages | 9 |

Journal | Applied Optics |

Volume | 40 |

Issue number | 33 |

Publication status | Published - Nov 20 2001 |

Externally published | Yes |

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### All Science Journal Classification (ASJC) codes

- Atomic and Molecular Physics, and Optics

### Cite this

*Applied Optics*,

*40*(33), 6121-6129.

**Analysis of the enhancement of backscattering by nonspherical particles with flat surfaces.** / Iwasaki, Suginori; Okamoto, Hajime.

Research output: Contribution to journal › Article

*Applied Optics*, vol. 40, no. 33, pp. 6121-6129.

}

TY - JOUR

T1 - Analysis of the enhancement of backscattering by nonspherical particles with flat surfaces

AU - Iwasaki, Suginori

AU - Okamoto, Hajime

PY - 2001/11/20

Y1 - 2001/11/20

N2 - We examine backscattering by analyzing large nonspherical particles with flat surfaces for which where the size is much larger than the wavelength, using ray optics and diffraction theory. We show that the backscattering cross section for rectangles can be 1 order of magnitude larger than that for spheres with same geometrical cross sections, depending on the orientation of the particles. Then we show that there is a difficulty in estimating the backscattering cross section for hexagonal columns with the available solutions but that it is possible to estimate the integration of the differential scattering cross section over small solid angles in backward directions. The integral values for hexagonal columns are found to be more than 1 order of magnitude larger than that for spheres with the same volume. As an application, the use of power from hexagonal columns for lidar observations is analyzed. Unlike for spherical particles with their dependence on Z-2 (where Z is the distance between the particle and the detector), for nonspherical particles such dependence varies with the particles' nonsphericity, such as shape and orientation: Z0 for a hexagonal plate randomly oriented in the horizontal plane; Z-1 for a hexagonal column randomly oriented in the horizontal plane.

AB - We examine backscattering by analyzing large nonspherical particles with flat surfaces for which where the size is much larger than the wavelength, using ray optics and diffraction theory. We show that the backscattering cross section for rectangles can be 1 order of magnitude larger than that for spheres with same geometrical cross sections, depending on the orientation of the particles. Then we show that there is a difficulty in estimating the backscattering cross section for hexagonal columns with the available solutions but that it is possible to estimate the integration of the differential scattering cross section over small solid angles in backward directions. The integral values for hexagonal columns are found to be more than 1 order of magnitude larger than that for spheres with the same volume. As an application, the use of power from hexagonal columns for lidar observations is analyzed. Unlike for spherical particles with their dependence on Z-2 (where Z is the distance between the particle and the detector), for nonspherical particles such dependence varies with the particles' nonsphericity, such as shape and orientation: Z0 for a hexagonal plate randomly oriented in the horizontal plane; Z-1 for a hexagonal column randomly oriented in the horizontal plane.

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M3 - Article

VL - 40

SP - 6121

EP - 6129

JO - Applied Optics

JF - Applied Optics

SN - 1559-128X

IS - 33

ER -