Basics of Navigation

Question 1

What acronym helps with bearing calculations?

Answer 1

C D M V T DR TT C G

Question 2

Define: grivation.

Answer 2

The sum of variation and convergence.

Question 3

Why is grivation useful?

Answer 3

It allows direct conversion between grid and magnetic.

Question 4

Given two latitudes, how to calculate ΔΦ?

Answer 4

Same hemisphere: subtract the smaller latitude from the larger

Opposite hemispheres: add the latitudes

If meridians add up to 180°, subtract both latitudes from 180° to obtain ΔΦ.

Question 5

Given latitudes, how to calculate the distance in nm between two positions?

Answer 5

Multiply ΔΦ by 60.

If longitudes are different but they add up to 180°, subtract both latitudes from 180° to and multiply the result by 60 to obtain the distance.

Question 6

Express the following changes of latitude in nm (assuming fixed longitude):

(a) 360°

(b) 180°

(c) 90°

(d) 45°

(e) 1°

Answer 6

(a) 21,600 nm
(b) 10,800 nm
(c) 5,400 nm
(d) 2,700 nm
(e) 60 nm