Reflectivity - Garmin G500 Pilot's Manual

Link Page. For the NEXRAD legend, select the LEGEND soft key when NEXRAD
is selected for display.
The display of radar coverage is always active when either NEXRAD or
ECHO TOPS is selected. Areas where NEXRAD radar coverage and Echo Tops
information is not currently available or is not being collected are indicated in
grayish-purple.
4.8.5.1

Reflectivity

Reflectivity is the amount of transmitted power returned to the radar receiver.
Colors on the NEXRAD display directly correlate to the level of detected
reflectivity. Reflectivity as it relates to hazardous weather can be very complex.
The role of radar is essentially to detect moisture in the atmosphere. Simply
put, certain types of weather reflect radar better than others. The intensity of a
radar reflection is not necessarily an indication of the weather hazard level. For
instance, wet hail returns a strong radar reflection, while dry hail does not. Both
wet and dry hail can be extremely hazardous.
The different NEXRAD echo intensities are measured in decibels (dB) relative
to reflectivity (Z). NEXRAD measures the radar reflectivity ratio, or the energy
reflected back to the radar receiver (designated by the letter Z). The value of Z
increases as the returned signal strength increases.
4-38
Figure 4-25 NEXRAD Weather Legend
Garmin G500 Pilot's Guide 190-01102-02 Rev. E