星载单光子激光雷达在浅水域测深方面展现出巨大的潜力,但其接收到的点云数据中存在大量噪声,给高程信息的提取带来了困难。目前,基于OPTICS(Ordering Points to Identify the Clustering Structure)的去噪算法因其精度高,在强背景噪声...星载单光子激光雷达在浅水域测深方面展现出巨大的潜力,但其接收到的点云数据中存在大量噪声,给高程信息的提取带来了困难。目前,基于OPTICS(Ordering Points to Identify the Clustering Structure)的去噪算法因其精度高,在强背景噪声下表现良好,得到了广泛的应用,但此算法在水底附近区域存在去噪效果不佳的现象。为了解决这个问题,文章提出了一种参量自适应的OPTICS单光子点云去噪算法,该算法与现有OPTICS算法固定输入参数的方式不同,是通过场景自适应获取更合适的输入参数来保证水底附近区域光子的分布参数的测量准确性,从而提升水底附近区域的去噪效果。凝聚度结果显示,新算法在水底附近区域的去噪效果较现有OPTICS算法提升了约13.67%,可为之后的水深测量等工作提供更高精度的单光子点云图像。展开更多
With good randomness and high sensitivity to initial values,chaotic sequences have been extensively used in secure communication.Real chaotic sequences are highly sensitive to initial values.It is an analog quantity i...With good randomness and high sensitivity to initial values,chaotic sequences have been extensively used in secure communication.Real chaotic sequences are highly sensitive to initial values.It is an analog quantity in the domain of attraction,which is not conducive to the transmission of digital signals.In order to improve the stability,real chaotic sequences can be quantized into digital chaotic sequences.According to the relationship between the information rate and the symbol rate,the symbol rate of binary sequence is the same as the information rate.The information rate can be doubled by quantizing a real-valued sequence into a quaternary sequence.The chaotic sequence has weak periodicity.Moreover,the periodicity of binary digital chaotic sequences is much weaker than that of quaternary chaotic sequences.Compared with the multi-dimensional chaotic map,the one-dimensional chaotic map has small key space and low security.In this paper,a new real-valued chaotic sequence is generated based on the chaotic matrix method constructed by Logistic map and Kent map.Two quantization methods are used to digitize the real-valued chaotic sequence to obtain the quaternary digital chaotic sequence.Moreover,the randomness,the time series complexity and the correlation of the new quaternary chaotic sequence are compared and studied.The simulation results demonstrate that the quaternary digital chaotic sequence obtained by the chaotic matrix has good randomness and correlation.展开更多
文摘星载单光子激光雷达在浅水域测深方面展现出巨大的潜力,但其接收到的点云数据中存在大量噪声,给高程信息的提取带来了困难。目前,基于OPTICS(Ordering Points to Identify the Clustering Structure)的去噪算法因其精度高,在强背景噪声下表现良好,得到了广泛的应用,但此算法在水底附近区域存在去噪效果不佳的现象。为了解决这个问题,文章提出了一种参量自适应的OPTICS单光子点云去噪算法,该算法与现有OPTICS算法固定输入参数的方式不同,是通过场景自适应获取更合适的输入参数来保证水底附近区域光子的分布参数的测量准确性,从而提升水底附近区域的去噪效果。凝聚度结果显示,新算法在水底附近区域的去噪效果较现有OPTICS算法提升了约13.67%,可为之后的水深测量等工作提供更高精度的单光子点云图像。
基金Support by the National Natural Science Foundation of China(No.61801173)。
文摘With good randomness and high sensitivity to initial values,chaotic sequences have been extensively used in secure communication.Real chaotic sequences are highly sensitive to initial values.It is an analog quantity in the domain of attraction,which is not conducive to the transmission of digital signals.In order to improve the stability,real chaotic sequences can be quantized into digital chaotic sequences.According to the relationship between the information rate and the symbol rate,the symbol rate of binary sequence is the same as the information rate.The information rate can be doubled by quantizing a real-valued sequence into a quaternary sequence.The chaotic sequence has weak periodicity.Moreover,the periodicity of binary digital chaotic sequences is much weaker than that of quaternary chaotic sequences.Compared with the multi-dimensional chaotic map,the one-dimensional chaotic map has small key space and low security.In this paper,a new real-valued chaotic sequence is generated based on the chaotic matrix method constructed by Logistic map and Kent map.Two quantization methods are used to digitize the real-valued chaotic sequence to obtain the quaternary digital chaotic sequence.Moreover,the randomness,the time series complexity and the correlation of the new quaternary chaotic sequence are compared and studied.The simulation results demonstrate that the quaternary digital chaotic sequence obtained by the chaotic matrix has good randomness and correlation.
