I'm working with data in latitude/longitude grid form in a non-GIS specialised package (MATLAB) and wish to apply spatial filters to it.
As this data contains a broad range of latitudes and is centred on the North Pole, I need to account for the spacing between points changing with latitude. For example, if I wanted to apply a simple Gaussian filter of radius X km, I can't just convert that radius to Y cells and go - there has to be some kind of correction as the filter width in terms of cells will change with latitude.
How do I attack this problem? Something to do with weighting by latitude?