4. DSL

Question 1

SOW vs SOG

Answer 1

Speed relative to the water or to the ground.

SOG accounts for the current of the water.

Question 2

What are some error in DSL?

Answer 2

Error in transducer orientation: must be 60 degrees with keel

Error from motion

Question 3

What are the DSL main components

Answer 3

Electronics Unit
Master Display Unit
Digital Filter Assembly
Transducer Assembly

Question 4

How does the DSL work?

Answer 4

Forward and aft transducers send out pulse trains. The frequency shift is measured, speed calculated, and averaged.

Question 5

DSL Operating Modes

Answer 5

Sea: 3.1m to 3.6m

Shallow: 0.3 to 1.8m

Question 6

DSL Frequency

Answer 6

2 MHz

Question 7

How long are the DSL pulses

Answer 7

1.1 ms

Question 8

How much power in DSL

Answer 8

10 W

Question 9

DSL Beamwidth

Answer 9

1.5 degree

Question 10

DSL accuracy

Answer 10

1%

Question 11

DSL Interfaces

Answer 11

Navigational Switchboards
Ships Power
Trimble GPS - Digital Filter

Question 12

Examples of mechanical logs

Answer 12

Impeller
Prop RPM
Pitometer

Question 13

What is a limitation with the DSL?

Answer 13

Innaccuracy going >5 knots astern

Question 14

Why DSL so important?

Answer 14

Used for FCS