Relative Vs True

Question 1

What is relative motion?

Answer 1

Object moving in respect to your vessel

Question 2

What is true motion?

Answer 2

Object moving in respect to the ground.

Question 3

Relative input
Compared to
True input?

Answer 3

Relative- No speed or gyro required.
True- log speed and gyro required.
-sea stab- stw
-ground stab-SOG
-gps or Doppler log

Question 4

Relative- visual
True visual?

Answer 4

R- own ship- no trail.
T- own ship has trail.

Question 5

Relative own ship vs true own ship

Answer 5

R- own ship on Center of ppi

T- own ship moves across the ppi reset by operator or automatically when approaching the edge.

Question 6

Relative motion display relative to?
True motion display relative to?

Answer 6

R- to the observer
T- to sea stab, the water. Ground stab, the ground.

Question 7

Advantages of relative motion?

Answer 7

Good collision avoidance recognition.
Can obtain tidal rate from racon.
Parallel indexing.

Question 8

Advantages of true motion?

Answer 8

Aspect recognition is good.
Good for pilotage.
You can see moving targets.

Question 9

Disadvantages on relative?

Answer 9

TGT, SP, aspect requires resolution.

Question 10

Which motion of a ship is not affected by the ship using sea or ground stabilisation?

Answer 10

Relative motion.

Question 11

Which stab to not use when approaching land?

Answer 11

Sea stab

Question 12

In which, sea stab or ground stab, has no allowance for tidal stream or current?

Answer 12

Sea stab

Question 13

Which? Sea or ground.
Stationary targets do not move.

Answer 13

Sea stabilisation.

Question 14

On which? Ground or sea?
Land and buoys are stationary?

Answer 14

Ground.

Question 15

What is parallel indexing only on ground or sea?

Answer 15

Ground