Pulse Length; Tune - Sperry Marine Visionmaster FT ECDIS User Manual

ECDIS User Guide
To switch between operational modes click the radio button adjacent to the
mode.
1. In Transmit the white diagonal line on the transmit/standby icon is
removed (see Getting Started with ECDIS, Standby Mode), the
transceiver starts transmitting radar pulses and the ECDIS display
can be enabled to show radar video, see Radar Video Mode
2. In Standby the white diagonal line on the transmit/standby icon re-
appears, the pulse length selection and radar tuning adjustment
are disabled and any active Radar Video is automatically switched
off.

Pulse Length

The following pulse lengths are available, dependent on the range
restrictions detailed below:
•
Short Pulses (SP) are used at close range to improve the
discrimination and range accuracy of received echoes.
•
Long Pulses (LP) are used at long range to improve the ability of
the radar to pick out targets at distance.
•
Medium Pulse (MP) is a pulse length used as an optimum
between discrimination and long range detection.
Pulse lengths are restricted to the following scale ratios:
•
SP is available on the 1:30,000 scale ratio and below.
•
MP is available in the 1:8,000 to 1:200,000 scale ratios.
•
LP is available at 1.40,000 scale ratio and above.

Tune

For a Master display there are three tuning controls:
•
AFC on/off
•
Manual fine tune
•
Coarse tune
In a multi-node system the coarse and fine tune levels are distributed and
used by other nodes on the system.
For accurate tuning to be achievable, coarse tuning must have been
correctly adjusted during initialisation. Refer to Chapter 2 `Diagnostics and
Commissioning' in Volume 2 of the VMFT Ship's Manual.
The current level of tuning is indicated by the shaded bar below the two
modes. This bar indicates the level in percentage terms with 0% on the
left, 100% on the right.
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Radar
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