title: Simulation of the inhomogeneous medium with a self-adapting grid.
abstract: It is difficult to solve the problem of tracing rays through an inhomogeneous medium such as the atmosphere or a flowing liquid with the existing methods whose refractive distribution cannot be characterized by any combination of formulas. A new method is developed to efficiently describe such a medium. The method essentially consists of characterizing the inhomogeneous medium with a self-adapting grid, the cell size of which can be automatically varied according to the gradient of the refractive index at each position within the medium. The advantage of this method is its capability to trace rays through a medium with random refractive distribution in an accurate way. To test its correctness, the ray trace through a regular gradient medium has also been made with this method, and the results are compared with those from other commercial lens design codes. It is shown that for appropriate parameter settings this method can obtain great accuracy.
authors.affiliation: State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou, China. dengshitao@zju.edu.cn
authors.forename: Shitao
authors.initials: S
authors.lastname: Deng
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Li
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Cen
authors.forename: Shoufu
authors.initials: S
authors.lastname: Jian