Lesson 4

Question 1

What is broad band noise?

Answer 1

Energy is spread over a wide range spectrum and individual frequencies are not distinguished

Question 2

What is the broad band effect?

Answer 2

Caused by multiple paths of broad band energy reflecting off the sea bed

Question 3

What is the Lloyds Mirror effect?

Answer 3

Caused by multiple paths of broad band energy reflecting from the surface. Allowing depth to be calculated

Question 4

What is narrow band?

Answer 4

When energy is concentrated in one discrete spectrum

Question 5

What are transients?

Answer 5

Noise which occur over a short or long term over irregular intervals

Question 6

What information do you find on a lofargram?

Answer 6

Time
Frequency
Intensity
Colour (bearing)

Question 7

What is reinforcement?

Answer 7

When a system can’t distinguish between two distinct sound sources so it over lays them to give a stronger intensity single line

Question 8

What is predominance?

Answer 8

How many harmonics of a specific sound you are seeing