一种改进的DQG格网编码与经纬度高效转换算法

格网编码与经纬度间的转换效率是影响格网应用的关键因素。现有转换算法难以满足海量空间大数据的实时计算与分析需求,效率有待提升。为此,该文提出一种改进的DQG格网编码与经纬度高效转换算法:首先,引入二进制DQG格网编码代替四进制编码;然后,根据DQG格元的分布特征推导出格元行号和经度差的关系,以此改进格元列号的计算过程;最后,使用查找表进行Morton码的编码和解码,以提高转换效率。实验结果表明,该文提出的DQG格网编码与经纬度转换算法的平均效率分别是四进制DQG、单层二维SDZ算法的20.15倍和4.58倍,基本满足海量格网数据的实时转换与计算需求,为海量空间大数据的高效计算与分析奠定了基础。

An Improved Efficient Conversion Algorithm between DQG Grid Code and Geographic Coordinate

The conversion efficiency between grid code and geographic coordinate is one of the key factors affecting grid applications.The efficiency of the existing conversion algorithms need to be improved,which is difficult to meet the real-time calculation and analysis requirements of massive spatial data.Therefore,an efficient conversion method between DQG grid code and geographic coordinate is proposed in this paper.The main contents are as follows.Firstly,the binary DQG grid code is introduced to replace the quaternary code.Then,according to the distribution characteristics of DQG grid cells,the relationship between row number of grid cell and longitude difference is deduced,and the calculation of column number of the grid cell is improved.Finally,the efficient LUT method of Morton encoding and decoding is used.The experiment results show that the average computational efficiency of the encoding/decoding algorithms proposed in this paper is 20.15 times of that of the quaternary DQG encoding/decoding,and also 4.58 times of that of the two-dimensional SDZ encoding/decoding.It basically meets the requirements of real-time conversion and calculation of massive grid data,which lays the foundation for efficient calculation and analysis of massive spatial data.