User's Manual

JMA-9172-SA Instruction Manual > 4.MEASUREMENT OF RANGE AND BEARING > 4.2 MEASUREMENT OF RANGE AND
BEARING
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4
4.2 MEASUREMENT OF RANGE AND
BEARING
Target position on the RADAR screen
RADAR antenna transmits pulses of radio waves. The object returns the wave
(radar echo) to the antenna. So on the RADAR screen the leading edge of echo is
the actual target position. The length of echo is dependent on the transmitted pulse
length.
Point the cursor to the leading edge of echo to measure the target range or to make
a mark on the target.
Fig 4-1: Transmitting-Receiving of RADAR
Fig 4-2: Relation of echo, target range and pulse length
Pulse of radio wave
RADAR echo
0
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Target range
Pulse length
Own ship's position