The slope calculation algorithm is one of the most widely used geospatial algorithms employing the 3x3 moving window technique (along with calculation of aspect, curvature and flow direction). This work presents an approach consisting of transforming a slope algorithm from a sequential form into a version that can exploit vector and parallel traits of multicore architectures with vector instructions. This approach allows us to take advantage of the potential of the modern multicore processors. The basic idea for optimizing the 3x3 moving window computation is to split the equation used to calculate the result into parts that operate on data that are known to exist in adjacent memory locations. The research was conducted on two multicore architectures without the change in the code — the older architecture was Sandy Bridge and the newer one was Haswell (with more cores). The efficiency of the developed slope algorithm was verified in practice with the use of DEM files of the same resolution but of different sizes. We showed through the numerical experiments that our approach gives better time performance than the original algorithm (and other tools) — and with no loss of accuracy.

坡度计算算法是采用 3x3 移动窗口技术（以及坡向、曲率和流向的计算）的最广泛使用的地理空间算法之一。这项工作提出了一种方法，包括将斜率算法从顺序形式转换为可以利用向量指令的多核架构的向量和并行特征的版本。这种方法使我们能够利用现代多核处理器的潜力。优化 3x3 移动窗口计算的基本思想是将用于计算结果的方程拆分为对已知存在于相邻内存位置的数据进行操作的部分。这项研究是在两种多核架构上进行的，代码没有发生变化——旧的架构是 Sandy Bridge，新的架构是 Haswell（具有更多核心）。使用相同分辨率但不同大小的DEM文件在实践中验证了所开发的坡度算法的效率。我们通过数值实验表明，我们的方法比原始算法（和其他工具）提供了更好的时间性能，并且没有损失准确性。