Three-Dimensional Path Planning Based on Six-Direction Search Scheme.

In order to solve the problem of how to perform path planning for AUVs with multiple obstacles in a 3D underwater environment, this paper proposes a six-direction search scheme based on neural networks. In known environments with stationary obstacles, the obstacle energy is constructed based on a neural network and the path energy is introduced to avoid a too-long path being generated. Based on the weighted total energy of obstacle energy and path energy, a six-direction search scheme is designed here for path planning.

[Preliminary exploring of hyperspectral remote sensing experiment for nitrogen and phosphorus in water].

The content of nitrogen and phosphorus in the waters is an important index to measure water quality, and the technique of remote sensing plays a large role in monitoring the change in environment. The reflectance spectra of nitrogen and phosphorus with different concentrations were measured to discover their special features under pure water condition in the laboratory by hyperspectral remote sensing technique. The result shows that nitrogen has reflectance peaks at 404 and 477 nm, and phosphorus at 350 nm, and these reflectance peaks have a good correlation with their concentrations, then a quantitative retrieval model was deduced for nitrogen and phosphorus based on that.

[Evaluating eutrophic state of Taihu Lake by in situ hyperspectra].

In situ experiments including water quality analyzing and spectra measuring were conducted on Jun., 2004 and Aug., 2004 in Taihu Lake for 21 samples.