Instruction Manual

6 RA51/52/53/54/55 INSTRUCTION MANUAL – 05

2.3 Terms Specific to Radar

HM (Heading Marker)

This is a line-shaped marker used to indicate the forward direction

of your boat.

North Mark

The marker to indicate the direction North is a short line ap-

proximately 1/6 of the screen size. It only appears when the radar is

connected to a suitable heading source provided through NMEA,

10/12 bit serial or sin/cos.

Fig.2-9 Heading Marker and North Mark

Display modes five (+HS)

The RA51/52/53/54/55 has four display modes. Each refers to the top of the screen as it relates to

the direction of your boat's travel.

Fig.2-10 Display modes

Head Up (HU)

The heads up mode corresponds with your current heading and shows what's directly in front of

you at the top of the screen. It gives you the position of other targets around you relative to your

boat.

North Up (NU)

In this mode, North is at the top of the screen. This allows you to compare your position with a

chart as you navigate. Heading data input is required for this mode to function.

Course Up (CU)

This is similar to North up except that your boat's destination is at the top of the screen. A straight

line from the bottom to top of the screen is your course bearing.

0.75

0.25

HM(Heading Marker)

North Mark

Ship's

Heading

North

Scheduled

course

EBL

North

mark

Ship's locus

(not displayed on screen)

North North

Scheduled

course

0.75

0.25

0.75