TOPS threshold value

The configurable threshold value defines the minimum reflectivity that must present to be displayed in the image.

The first of the following images shows TOPS with a -20 dBZ threshold defined. In this image, the higher, less dense parts of the cloud are shown in the displayed image. In TOPS, using lower threshold values can help determine the height of surrounding precipitation. For example, a 50 dBZ TOP 1 km above the freezing level can be produced only by a vigorous convective storm, and is probably caused by the presence of hail.

In the second image, with a 40 dBZ threshold, higher part of the cloud is not shown in the displayed image because its reflectivity value is lower than the defined threshold.