Abstract

A statistical analysis for pattern recognition of small cloud particles sampled with a PMS-2DC probe

Highlights

  • Size spectra obtained from in situ measurements within clouds (Liou, 1992; Kinne and Liou, 1989) show that the number of small particles is very large, and that it is important for the determination of structural, optical and microphysical quantities such as liquid or ice water contents (LWC or IWC)

  • The representativeness of the sampled images depends on both the true air speed (TAS) clock frequency and the lapse rate of the photodiodes

  • Dx characterizes the nominal pixel size (25 lm) de®ned by the array of the photodiodes, Dy is the pixel size along theight direction

Read more

Summary

Introduction

Size spectra obtained from in situ measurements within clouds (Liou, 1992; Kinne and Liou, 1989) show that the number of small particles (size ranging from 25 lm to 200 lm) is very large, and that it is important for the determination of structural, optical and microphysical quantities such as liquid or ice water contents (LWC or IWC). The scattering properties of ice crystals (with hexagonal structure or even a more complex shape) di€er significantly from that of perfect spheres (as given by the Mie theory), and the spherical assumption induces quite large errors for the calculation of bulk quantities such as the liquid water path or optical thickness of the cloud. The objective was to de®ne a new automatic pattern recognition algorithm in order to di€erentiate the images of small hexagonal columns from those of spherical particles. Fouilloux et al.: A statistical analysis for pattern recognition of small cloud particles

Simulating the sampling of spherical particles and hexagonal columns
Results of the statistical analysis
Estimation of the volume of the particle
Images with 2 pixels
Images with at least 3 pixels
Summary and conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.