Simrad ARGUS FMCW 3G, User Manual

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Radar presentation and video processing | Argus Radar Operator Manual
The performance monitor ring should have a missing
angular sector of some 60° to 100°. This missing
sector is due to the RF beam really transmitted by
the antenna. Any RF power degradation between
the magnetron and the antenna output results in a
smaller angular ring interruption. When the angular
sector is reduced below 30°, the antenna section
requires service.
The ring’s width (thickness) is proportional to the tun-
ing condition. The width of the ring for a good and
correctly tuned radar will be approximately 2 NM.
The ring’s strength (difference between background
noise and ring’s noise) indicates the receiver noise
figure. If the receiver noise figure degradation is
more than 10 dB, the P.M. ring is no longer distin-
guishable from the background noise.
Some installations may not require the performance monitor function. In such case, the func-
tion and the button are disabled.
Power normal/boost
Pressing the “Power Normal” button (“TXRX interswitch menu (standard)” on page 77), the
“Power Boost” function will be displayed. This function permits operating with the radar pulse
lengths according to the following table. In both modes, (Normal or Boost), the functioning of
the system is the same, changing only the transmission pulse length.
Range scale (NM) Normal (µs) Boost (µs)
0.25 0.07 0.07
0.50 0.07 0.07
0.75 0.07 0.07
1.50 0.07 0.25
3 0.07 0.25
6 0.25 0.80
12 0.25 0.80
24 0.80 0.80
48 0.80 0.80
96 0.80 0.80
The operator has to operate carefully when selecting pulse length. The transmitted RF pulse
length (the amount of energy) is an important factor of radar characteristics, it determines the
range resolution, the minimum and the maximum radar detection range. Generally, the sys-
tem and the operator will select a longer pulse for longer detection range and shorter pulse
for better discrimination of nearby targets at short range, such as in harbour manoeuvring.
Be also aware that the more the operator uses the Power Boost, the faster the magnetron is
consumed.