Error Analysis and a New Arithmetic Study on Computing Horizontal Temperature Gradient in Marine GIS

There are three problems using current GIS software to calculate the horizontal temperature gradient of fishing grid. This work analyzed the errors caused by these problems, and presented a kind of new GIS algorithm of calculating the horizontal temperature gradient of fishing grid, and also presented multisection & single point change surface interpolation method for interpolating grid point temperature based on SST isoline. The results by our algorithms are better than results by ArcGIS.