Finding Range And Bearing Between Two Points - Furuno GP-150 Operator's Manual

5.4 Finding Range and
Bearing Between Two
Points
Selecting Course Sailing Method
The range and bearing to a destination are
calculated by two ways: Great Circle or
Rhumb Line. However, cross track error is
calculated by rhumb line only.
Great Circle: The great circle courseline is
the shortest course between two points on
the surface of the earth. (Imagine stretching a
piece of yarn between two points on the
earth.) However, this course requires
frequent change of heading to follow course
faithfully.
Rhumb Line: The rhumb line courseline is
the straight line drawn between two points on
a nautical chart. This course does not require
frequent changes of heading however it is not
the shortest since it follows the earth's
curvature.
1) Press MENU ESC, 9 and 1 to display the
PLOTTER SETUP menu.
PLOTTER SETUP
Memory Apportion
Bearing Ref.
Mag Variation
Calculation
User defined #1
User defined #2
User defined #3
User defined #4
ENT:Enter
MENU:Escape
Figure 5-19 PLOTTER SETUP menu
2) Press or to selection Calculation.
3) Press or to select R.L (Rhumb
Line) or G.C (Great Circle).
4) Press the NU/CU ENT key.
5) Press the MENU ESC key.
Trk = 1000 / 2000Pt
Mag
True
Auto
Man
(07q W) (00q E)
R.L
G.C
SOG
COG
RNG
BRG
5. STARTING FOR DESTINATION
Calculation Procedure
You can find the range and bearing between
two points by two waypoints or two latitude
and longitude positions.
1) Press MENU ESC and 5. The MANUAL
CALCULATION menu appears.
MANUAL CALCULATION
From
Waypoint No.
q .
To Waypoint No.
q .
Trial speed : Auto
Rng: . m
TTG: D H
: Cursor
ENT : Calculation
Figure 5-20 MANUAL CALCULATION menu
2) Choose two points by one of the methods
below.
Latitude and longitude positions
1) Press .
2) If necessary press to switch from North
latitude and to South latitude vice versa.
3) Key in latitude.
4) If necessary press to switch from West
longitude to East longitude and vice
versa.
5) Key in longitude.
6) Press .
7) Repeat 2-5 to enter other point.
Waypoints
1) Key in first waypoint number (001-999).
(000 is reserved for own ship position.)
2) Press twice.
3) Key in other waypoint number (001-999).
(Continued on next page)
q 
'N 'E
q 
'N 'E
Man
 kt)
(
q
Brg: .
M
MENU : Escape
: N/S, E/W
5-7