Bedienungsanleitung Furuno 1712 (Seite 26 von 36) (Englisch)

596219

Zoom out

Zoom in

Vorherige Seite

1/36

Nächste Seite

3.3 SART

Note: The SART (Search and Rescue

Transponder) information below is excerpted

from IMO SN/Circ 197 Operation of Marine

Radar for SART Detection.

A Search and Rescue Transponder (SART) may

be triggered by any X-Band (3 cm) radar within

a range of approximately 8 nm. Each radar

pulse received causes it to transmit a response

which is swept repetitively across the complete

radar frequency band. When interrogated, it first

sweeps rapidly (0.4 µs) through the band before

beginning a relatively slow sweep (7.5 µs)

through the band back to the starting frequency.

This process is repeated for a total of twelve

complete cycles. At some point in each sweep,

the SART frequency will match that of the

interrogating radar and be within the pass band

of the radar receiver. If the SART is within range,

the frequency match during each of the 12 slow

sweeps will produce a response on the radar

display, thus a line of 12 dots equally spaced by

about 0.64 nautical miles will be shown.

When the range to the SART is reduced to

about 1 nm, the radar display may show also

the 12 responses generated during the fast

sweeps. These additional dot responses, which

also are equally spaced by 0.64 nm, will be

interspersed with the original line of 12 dots.

They will appear slightly weaker and smaller

than the original dots.

9500 MHz

9200 MHz

Radar antenna

beamwidth

Screen A: When SART

is distant

Screen B: When SART

is close

Lines of 12 dots

are displayed in

concentric arcs.

Echo of SART

Position of

SART

Own ship's

position

Own ship's

position

SART mark

length

Radar receiver

bandwidth

Sweep time

7.5 µs

95 µs

Sweep start

High speed sweep signal

Low speed sweep signal

24 NM

1.5 NM

Position of

SART

Echo of

SART

Figure 3-6 Appearance of SART signal

on the radar display

General procedure for detecting SART

response

1. Use the range scale of 6 or 12 nm as the

spacing between the SART responses is

about 0.6 nm (1125 m) to distinguish the

SART.

2. Turn off the automatic clutter suppression.

3. Turn off the Interference Rejector.

General remarks on receiving SART

SART range errors

When responses from only the 12 low frequency

sweeps are visible (when the SART is at a

range greater than about 1 nm), the position at

which the first dot is displayed may be as much

as 0.64 nm beyond the true position of the

SART. When the range closes so that the fast

sweep responses are seen also, the first of

these will be no more than 150 meters beyond

the true position.

Radar bandwidth

This is normally matched to the radar

pulselength and is usually switched with the

range scale and the associated pulselength.

Narrow bandwidths of 3-5 MHz are used with

long pulses on long range and wide bandwidths

of 10-25 MHz with short pulses on short ranges.

Any radar bandwidth of less than 5 MHz will

attenuate the SART signal slightly, so it is

preferable to use a medium bandwidth to ensure

optimum detection of the SART.

Missbrauch melden von Frage und/oder Antwort

Libble nimmt den Missbrauch seiner Dienste sehr ernst. Wir setzen uns dafür ein, derartige Missbrauchsfälle gemäß den Gesetzen Ihres Heimatlandes zu behandeln. Wenn Sie eine Meldung übermitteln, überprüfen wir Ihre Informationen und ergreifen entsprechende Maßnahmen. Wir melden uns nur dann wieder bei Ihnen, wenn wir weitere Einzelheiten wissen müssen oder weitere Informationen für Sie haben.

Furuno 1712 Seite 26

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Andere Handbücher von Furuno 1712

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info