Kongsberg Simrad RA85 - Page 75

RA83/84/85/93/94/95 Series Chapter 5
Operation Manual Basic Operation
Picture resolution
The picture resolution depends on the bearing and range discriminations that are
solely determined by the antenna horizontal beam width and the transmission pulse
length. These factors are defined in the following explanations and illustrations.
(1) Bearing discrimination
The bearing discrimination is defined as the minimum bearing where two targets of
the same distance are displayed as two independent images on the screen. The
bearing discrimination is determined by the aerial horizontal beam width.
The distance between two targets
in azimuth is shorter than the rada
r
beam width.
The distance between two targets
in azimuth is longer than the rada
r
beam width.
(2) Range discrimination
The range discrimination is defined as the minimum distance where two different
targets situated in line on the same bearing are shown separated. The range
discrimination is dependent on the transmission pulse length.
Length of
transmission
pulse
Range
Between two
targets
Radar antenna
When the ran
g
e between two tar
g
ets is wider than the transmission
p
ulse len
g
th.
Echoes from
two targets are
separated
Transmission
pulse
Range
between two
tar
g
ets
When the range between two targets is narrower than the
transmission pulse length.
Echoes from
two targets are
overlapped (not
separated)
Radar antenna
93142105-02 5-19