5.1.3NEXRAD Intensity
Colors are used to identify the different NEXRAD echo intensities (reflectivity) measured in dBZ (decibels of Z). “Reflectivity” is the amount of transmitted power returned to the radar receiver. Reflectivity (designated by the letter Z) covers a wide range of signals (from very weak to very strong). So, a more convenient number for calculations and comparison, a decibel (or logarithmic) scale (dBZ), is used. The dBZ values increase as the strength of the signal returned to the radar increases.
5.1.4NEXRAD
When enabled, NEXRAD weather information is shown. Composite data from all of the NEXRAD radar sites in the United States is shown. This data is composed of the maximum reflectivity from the individual radar sweeps. The display of the information is
The NEXRAD option has selections of Regional, CONUS, or Combined NEXRAD (only available with GTN units). CONUS NEXRAD includes a composite of available NEXRAD radar imagery across the 48 states. Regional NEXRAD is a composite of available NEXRAD radar imagery in a local area, showing a more detailed image than CONUS NEXRAD.
Continental US NEXRAD (CONUS)
The Display CONUS NEXRAD selection shows NEXRAD radar information for the entire continental United States. CONUS NEXRAD data is updated every 15 minutes. The resolution of displayed CONUS NEXRAD data is approximately 10 kilometers (5.4 NM). The intensity level reflected by the square will be the highest level sampled within the area covered by each block.
Regional NEXRAD
The Regional NEXRAD selection shows regional NEXRAD radar information within 500 miles of the aircraft location. The resolution of displayed Regional NEXRAD data is approximately two kilometers (1.08 NM).
Combined NEXRAD
Regional NEXRAD data within 150 NM of the aircraft location and CONUS NEXRAD data everywhere else. The two types of NEXRAD are separated by a white stippled border. This boundary is updated whenever new Regional or CONUS NEXRAD data is received.
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