Cloud Droplets Particle Detection Method Based On Digital Holographic Research

In terms of weather modification, the cloud droplets particle detection is one of the important measures. It provides important information for artificial weather modification effectively. Due to the complexity of structure of clouds, cloud seeding area is difficult to determine accurately. In the process of weather modification, obtaining accurately the internal distribution of clouds is greatly significance.Digital holography is a new kind of holographic imaging technology. It uses the new type of optical CCD detector to instead of the traditional optical dry plate as the material of recording hologram. It is through the use of computer to simulate the process of light diffraction, to obtain the distribution of the field of holography. Finally, it can achieve the whole process of digital hologram, including recording, storage, transmission and reconstruction. With the rapid development of modern high resolution CCD and computer technology, digital holographic technology is widely used in the particle measure, because it can realize to the measurement of three-dimensional particle field and obtain detail parameters.This article adopts the in-line digital holographic method to records of laboratory simulation of particles, and obtains the particle digital hologram. In the end, some parameters of the groups of particles were obtained by the application of computing. Such as, the three-dimensional distribution of particle, and monomer characteristic parameters, including shape, particle size, ovality.This paper studies the traditional holography and digital holography recording and reproduction theory, analyzes the math expression of the optical holographic recording process respectively from two aspects of analytical solution and numerical solution, compares the two different kinds of holographic representation algorithm, studies the plane wave recording in-line digital hologram system to measure particle.After preprocessing of the image data, the image noise can been reduced. It studies a variety of method of particles found focus location, which using gray-scale synthesis method to extract for gray level, to achieve three-dimensional distribution of particles. All measurements in the process of measurement need to use the threshold to extract particles in the particles found. Finally, extracted the particle size is estimated.Designing experiment system, and completing the construction of the experimental system. Including the holography for homemade aluminum dust particles and water droplets, using convolution representation algorithm, gray-scale synthesis sentenced to focus on the image data processing and the corresponding analysis.This paper proves the feasibility of in-line digital holographic device that is applied to the clouds parameter measurement. It completed the construction of the experimental system, and the measurement of particle of the experimental simulation.