There is a lot of common code between plot_ppi in radarmap display and plot_surface and plot_surface_contour in gridmapdisplay which could be placed in auxiliary functions.
Moreover we misunderstood the fact that add_image already takes care of transforming the image from its native projection to the projection of the axes where it has to be added and at the moment when a background map is used the axes projection are changed to that of the background map which would not be necessary.
There is a lot of common code between plot_ppi in radarmap display and plot_surface and plot_surface_contour in gridmapdisplay which could be placed in auxiliary functions.
Moreover we misunderstood the fact that add_image already takes care of transforming the image from its native projection to the projection of the axes where it has to be added and at the moment when a background map is used the axes projection are changed to that of the background map which would not be necessary.