Quick Installation Guide

Quick Installation Guide
Document
WERA4-Quick-US-200918
Page 2 of 73
1.1 Intended Use and Safety Instructions
 The WERA system is a short wave radar device for oceanographic applications.
To run the system the user has to get an official permission from the local
authorities to operate radio wave transmitting systems.
 This system complies with part 15 of the FCC rules. Operation is subject to the
condition that this system does not cause harmful interference.
 The WERA system is designed for radar measurements at the ocean coast line. The
transmitter antennae array will transmit a continuous RF signal with a power less than
10 Watts per antenna. Even if this low power won’t generate any harmful voltage or
radiation, it is required to take care that the installation of the transmit antenna system
complies with the FCC requirements.
Depending on the radar operation frequency, the antenna gain and the cable loss
between power amplifier and Tx antenna system the minimum distance “D” can be
calculated:
D=
√
P
4∗π∗PD
P = P
out
+ G
ant
- Att
cable
PD = 900 / f
2
where
D: minimum distance in cm between human and
antenna
P: radiated power in mW,
P
out
: Output power of Power amplifier in dBm
G
ant
: Antenna gain of transmit antenna system in dB
Att
cable
: Cable attenuation in dB for cable from power
amplifier output to transmit antenna
PD: Power Density in mW/cm
2
f: Radar operating frequency in MHz
The formulary to calculate the value of the power
density is given in the FCC document “Radiofrequency
radiation exposure limit” 47CFR § 1.1310
Caution: It is required to apply adequate precautions, e.g. fences with warnings signs,
to prevent that humans enter the area around the transmit antenna system
which is closer than the minimum distance as calculated above.