NAV 5

通報

問題一覧

What does RADAR stand for?

Radio Detection and Ranging

What is the suitable radio wave length to use at closer range?

Short

What is the suitable radio wave to use, at farther range?

Long

How do you define Bearing discrimination?

It is the ability to discriminate between two small objects close together at the same range

How do you define Range discrimination?

it is the ability to discriminate between two small objects close together at the same bearings

What do occur when the radiation from the aerial is intercepted by obstructions such as the mast, funnel, etc. onboard the vessel?

Blind and shadow sectors

What may occur due to the obstructions close to the site of the aerial which may reflect some of the radar energy on both its outward and return journey?

Indirect echoes

The importance of minimum range detection is recognized by the IMO performance standard. What is the range required by the IMO performance standard that specific target types be clearly displayed

down to a minimum range of 50 meters.

What pulse settings is recommended with targets beyond the rain?

Long pulse

How many cm is the wavelength of X-band radars?

3cm

How many cm is the wavelength of S-band radars?

10cm

What is the effect of sub-refraction on your RADAR?

The effect of sub- refraction is to bend the radar rays upward and thus decreases the maximum range at which the contacts maybe detected.

The radar rays are reflected downwards to the surface of the sea, then reflected upward reflected downwards again within the duct, and so on continuously.

Surface duct

Which band is recommended to use when it is raining?

S-band

The amount of energy which is returned towards the antenna, as opposed to that energy which is absorbed and scattered by the target is dependent upon the following five (5) prime characteristics of the target.

aspect, surface texture, materials, shape and size

Which of these precipitations has the most effect on radar range and target detection?

rain

It is a condition in calm weather with no turbulence where there is an upper layer of warn dry air over a surface layer of cold moist air. This normally occurs in the tropics when warn land breeze blows over the cooler ocean currents.

Super refraction

The phenomena, occurs during extreme cases of super-refraction. Energy radiated at angles of 1 (one) degree or less maybe trapped in a layer of the atmosphere called ______________.

Surface radio duct

It is a phenomenon cannot be described as precipitation but, as the effects are similar.

Dry sand and dust haze

It is an expression which attempts to formalize the relationship between the maximum range at which a target can be detected and the parameters on which that range depend

Range equation

It is caused by starting the sweep on the indicator before the energy leaves the antenna.

Fixed range error

What is Range resolution?

It is a measure of the capability of the radar to display as separate indication the echoes of two contacts which are on the same bearing and close together.

Interference can be filtered out by comparing the signals present in successive range and rejecting those which do not appear on successive lines or by pressing the button IR. What do IR mean?

Interference Reject

When side echoes are observed where they have not been seen before, their cause should be determined the first suspect should be:

dirty antenna

It occurs when a target is close and the energy bounces back and forth between the hulls of the target and by the observing ship, with some of the energy entering the antenna at each return.

Multiple echoes

What is the maximum heading indicator error?

1 degree

The standard on minimum range and range performance continues to be met even if the vessel is rolling and pitching up to _____________.

10 degrees

The maximum duration set by the IMO performance standards which requires that, after switching on from cold, the equipment should become full operational______________.

within 4 minutes

It is a free running oscillator, which generates a continuous succession of low voltage pulses known as synchronizing pulses or trigger pulses; commonly they are referred to as simply triggers

trigger generator

For long range targets, which radar band is recommended?

s-band

MARCOM

Vaper Namit · 37問 · 1年前

MARCOM

37問 • 1年前

NAV 4

NAV 4

SEAM 7

SEAM 7

NAV 1

Vaper Namit · 30問 · 1年前

NAV 1

30問 • 1年前

SEAM 1

SEAM 1

SEAM 2

Vaper Namit · 15問 · 1年前

SEAM 2

15問 • 1年前

NAV 3

Vaper Namit · 24問 · 1年前

NAV 3

24問 • 1年前

NAV 6

NAV 6

NAV 7

NAV 7

D-WATCH 1

Vaper Namit · 20問 · 1年前

D-WATCH 1

20問 • 1年前