Aids to Navigation

Question 1

What are the errors of the GPS?

Answer 1

1. Satellite clock bias error
2. Relativity error
3. Satellite positional error
4. GDOP (Geometric Dilution of Precision)
5. Atmospheric and Ionospheric delays
6. Solar Activity
7. Multi Path Errors

Question 2

What are the errors of the Echo Sounder?

Answer 2

1. Layers of water with different speeds of sound
2. Shoals of fish
3. Seaweed
4. Faults
5. Artificial noises/vibrations
6. Tidal streams/Turbulence
7. Side Errors from objects not directly underneath the vessel

Question 3

How can double echos and multiple echos be removed?

Answer 3

Reduce the sensitivity on the transceiver