isoecho contour mode

A mode of operation of a monochromatic weather radar. When the button for this mode is pressed, areas of precipitation corresponding to red on a color screen turn black. This leaves the lighter green portion around the black area, allowing changes in rainfall intensity to be better evaluated. A thin line of green indicates a rapid change in rainfall rates (steep rainfall gradient), and such an area should not be penetrated because of the inferred high degree of turbulence.