Garmin gnc 420 用户指南
GNC 420/420A Pilot’s Guide and Reference
11-13
SECTION 11
ADDITIONAL FEATURES
NEXRAD Intensity
Colors are used to identify the different NEXRAD echo intensities (reflectivity) measured in dBZ (decibels of Z).
Reflectivity (designated by the letter Z) is the amount of transmitted power returned to the radar receiver. The dBZ values
increase as returned signal strength increases. Precipitation intensity is displayed on the GNC 420 units using colors
represented by the dBZ values listed in Table 11-3.
increase as returned signal strength increases. Precipitation intensity is displayed on the GNC 420 units using colors
represented by the dBZ values listed in Table 11-3.
Display
dBZ
Rain
(inches/hour)
Snow
(inches/hour)
Source of NEXRAD Echo
GDL 49
GDL 69
Atmos
Cloud
Rain
Snow
Sleet
Hail
<-10
.00
.00
-10
.00
.00
-5
.00
trace
0
.00
trace - .05
Very Light
5
.00
trace - .10
Light
10
0 – trace
.10
Light
Light
15
.01
.1-.2
Light
Light
20
.02
.2-.3
Light
Light
25
.05
.3-.5
Light
Light – Medium
30
.09
.5-.7
Light – Moderate
Moderate
35
.24
.7-1.0
Moderate
Heavy
40
.48
>1 or sleet
Heavy
Heavy
45
1.25
>1 or sleet
Heavy
Heavy
50
2.5
sleet
Intense
55
5.7
sleet
Extreme
60
12.7
Extreme
65
Extreme
70
Large
75
Large
Table 11-3 NEXRAD Intensity Colors
NOTE: The information presented in this Pilot’s Guide regarding NEXRAD is not meant to be comprehensive.
The NOAA website (www.noaa.gov) contains complete and detailed information regarding NEXRAD weather
radar operation and theory.
The NOAA website (www.noaa.gov) contains complete and detailed information regarding NEXRAD weather
radar operation and theory.