isoecho
From Glossary of Meteorology
On radar displays, a line or contour connecting all points of equal target signal strength or radar reflectivity factor, labeled, for example, in units of dBZ.
Such displays for radar or lidar (e.g., PPI, RHI, THI) can be generated in real time using grayshades or colors to show steps in the reflectivity pattern.
See echo contour.