Raytheon Anschuetz GmbH High Seas Products NSX-30U 用户手册
Synapsis Radar
with Nautoscan NX Pedestal
Operator Manual
Edition Sep 2015
3-1
4265.DOC020102
3
Theory of Operation
This chapter gives additional information about Radar operation and functions.
This chapter gives additional information about Radar operation and functions.
It explains terminology and describes a number of effects which have influence
on Radar performance and have to be considered by the operator.
on Radar performance and have to be considered by the operator.
A Radar uses a very high frequency radio wave (microwave) which has similar
properties to those of light regarding straightness and uniform velocity. The
Radar antenna radiates the fan shape fine microwave (fan beam) to the target
just as a search light throws the light beam to the target, and the reflected
microwave from the target returns to the antenna.
properties to those of light regarding straightness and uniform velocity. The
Radar antenna radiates the fan shape fine microwave (fan beam) to the target
just as a search light throws the light beam to the target, and the reflected
microwave from the target returns to the antenna.
The Radar does not use an continuous wave but radiates the wave for a very
short period (approx. 10-6 to 10-8 second .... called pulse) to measure the time
from when the wave is radiated till the reflected wave returns to the antenna. In
addition, with rotation of the antenna at a constant speed, the fan shape radio
wave radiated from the antenna scans around 360̊ - with the antenna at its
center - in order to detect the object.
short period (approx. 10-6 to 10-8 second .... called pulse) to measure the time
from when the wave is radiated till the reflected wave returns to the antenna. In
addition, with rotation of the antenna at a constant speed, the fan shape radio
wave radiated from the antenna scans around 360̊ - with the antenna at its
center - in order to detect the object.
3.1
Radar Plotting Terminology
• Bearing (AZIMUTH)
The horizontal direction of one point from another point, expressed as
the angle in the horizontal plane between a reference line and the
horizontal projection of the line joining the two points.
the angle in the horizontal plane between a reference line and the
horizontal projection of the line joining the two points.
− TRUE Bearing > Reference is true north
− RELATIVE Bearing > Reference is own ship’s heading
− RELATIVE Bearing > Reference is own ship’s heading
• Target Speed
− TRUE > Actual speed made good by target.
− RELATIVE > In relation to own ship’s movement
− RELATIVE > In relation to own ship’s movement
• Target Course
− TRUE > Direction of target movement referenced to true north.
− RELATIVE > Direction of target movement referenced to own ship bow.
− RELATIVE > Direction of target movement referenced to own ship bow.
• Closest Point of Approach (CPA)