Minimum Safe Operating Distances
When it is transmitting, the radar should be located in a position on the vessel that is at least this far
from people. IEC 60936-1, clause 3-27.1, specifies the maximum distances from the antenna at which radio
frequency (RF) levels can be expected.
These minimum safe distances apply for a transmitting radar with a rotating antenna, and are much larger
when the antenna is not rotating. If rotation of the antenna is obstructed for any reason, the transmitter will
automatically turn off.
IMPORTANT: The specified 100 W/m
2
minimum distance must be maintained between the antenna and the
occupational user and the specified 10 W/m
2
must be maintained between the antenna and the general public.
Under such configuration, the radio frequency radiation exposure limits set forth for a population/uncontrolled
environment are satisfied.
Model
100 W/m²
50 W/m²
10 W/m²
GMR Fantom 54
0.12 m (4.72 in.)
0.17 m (6.69 in.)
0.38 m (14.96 in.)
GMR Fantom 56
0.13 m (5.11 in.)
0.18 m (7.09 in.)
0.40 m (15.75 in.)
GMR Fantom 124
0.19 m (7.48 in.)
0.26 m (10.24 in.)
0.59 m (23.23 in.)
GMR Fantom 126
0.20 m (7.87 in.)
0.28 m (11.02 in.)
0.62 m (24.41 in.)
GMR Fantom 254
0.27 m (10.63 in.)
0.38 m (14.96 in.)
0.85 m (33.46 in.)
GMR Fantom 256
0.28 m (11.02 in.)
0.40 m (15.75 in.)
0.90 m (35.43 in.)
Antenna Specifications
Specification
Measurement
Type
End-fed slotted waveguide
Horizontal beam width
4 ft. antenna: 1.8 degrees
6 ft. antenna: 1.25 degrees
Horizontal side lobes
-23 dB within ±10 degrees of main
-30 dB outside ±10 degrees of main
Vertical beam width
22 degrees
Polarization
Horizontal
15
