User's Manual

NACOS Platinum
ED 3100 G 110 / 02 (2011-10)
Operating Instructions
A-1 General Information
A RADAR.fm / 10.11.11
A-14
In the table below the settings of the respective filters are described:
Table A / 5 Qualitative description of Enhance levels
Interference Rejection is a means to suppress interferences caused by other radars working on the
same frequency. For example, if two radars of the same kind operate very close to each other and the
PRF and signal frequency are similar or equal, the radars will influence each other with their pulses or
echoes. Circles or coils will appear on the PPI. With Interference Rejection on, most of those effects
will be eliminated by a filter that is able to detect those special signals. Targets will not be suppressed.
See also
A-Distortions of the RADAR Video in section 1.4.3.
Video Emphasis can be used to increase the detection of targets of the radar. Very strong echoes will
be shown in orange colour. It can help to decide whether an echo is one or two combined objects. For
example, without VE the echo is only a large yellow spot, with VE switched on it is visible that the yellow
spot contains 2 smaller orange dots, it can be decided that there is a structure in the yellow spot or that
there are two echoes very close to each other. The display of targets on the PPI will be improved, targets
will not get lost if VE is switched off. Also structures in land areas or in rainclouds or seaclutter can be
made more visible by the VE function, for instance a light house on a land area or buoys with only a
short distance to the land, whose echoes would normally melt into the ones of the land.
1.4.2 Achievable RADAR Range
The theoretically achievable radar range limited by the curvature of the earth depends on the height
of the antenna above the water surface and the height of the target, and is applicable under normal
atmospheric conditions - see the following table.
Table A / 6 Achievable RADAR Range
Whether radar targets can be detected up to this theoretical range, even with optimum video setting,
depends not only on the atmospheric conditions but also on the characteristics of the target:
Enhance
Off Low Medium High
Adaptive STC no no yes, but small
yes, medium
value
Correlation no
yes, with short time-
constant
yes, longer time-
constant than
„LOW“
yes, longer time-
constant than
„MEDIUM“
Target
enhancement
very little, small
targets just visible
little medium high
Antenna Height
Above Water Surface
Theoretically Achievable RADAR Range
at a Target Height of
1 m 3 m 10 m 30 m 100 m 300 m
1000
m
8 m 9 NM 12 NM 13 NM 18 NM 28 NM 44 NM 76 NM
15 m 11 NM 13 NM 16 NM 21 NM 31 NM 47 NM 79 NM
30 m 12 NM 16 NM 19 NM 23 NM 34 NM 50 NM 82 NM