Garmin GDL 88 用户手册
5-4
GDL 88 ADS-B Transceiver Pilot’s Guide
190-01122-03 Rev. A
5.1.3
NEXRAD 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.
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.
5.1.4
NEXRAD
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 color-coded to indicate the weather level severity.
FIS-B NEXRAD does not differentiate between frozen and liquid precipitation.
Refer to the previously shown legend for a description of the color code.
composed of the maximum reflectivity from the individual radar sweeps. The
display of the information is color-coded to indicate the weather level severity.
FIS-B NEXRAD does not differentiate between frozen and liquid precipitation.
Refer to the previously shown legend for a description of the color code.
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.
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.
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).
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.
white stippled border. This boundary is updated whenever new Regional or
CONUS NEXRAD data is received.