Target density on the sky for low- (upper panel) and high-resolution (lower panel) test surveys. Target density was calculated within a circle (with random location within a fixed sky area) of radius r as indicated in abscissa. Black lines show the total target density for a given resolution, coloured lines show target density for individual surveys. Solid lines show median target density on the sky, while dashed lines indicate the 90% quantiles. Due to the clustering of targets, the target density (90% quantile) increases towards small sky areas.