Evolution of Δp/p as minimization proceeds for various uniform spatial samplings (panel (a)) and of ﹩{\mathcal{J}}/{{\mathcal{J}}}_{0}﹩ and Δp/p for nonuniform sampling in latitude (panels (b) and (c)). Blue, black, and red refer to sampling restricted to the active band, the northern hemisphere, and the southern hemisphere, respectively. In the two last panels, a case with uniform sampling is also shown for comparison.