2.14 Measuring the Range

You can measure the range to a target three ways: by the range rings, by the cursor, and by the VRM (Variable Range Marker).

Measuring range by range rings

Count the number of rings between the center of the display and the target. Check the range ring interval and judge the distance of the echo from the inner edge of the nearest ring.

To turn the rings on or off, see the menu opera- tion later (Chapter 3).

Measuring range by cursor

Operate the trackball to place the cursor inter- section on the inside edge of the target echo, The range to the target, as well as the bearing, appears at the bottom of the display.

Measuring by VRM

1.Press either [VRM 1] or [VRM 2] key. The readout of the active marker is circum- scribed.

EBL

 

VRM

345.6°R

 

5.3 NM

23.0°R

12.5 NM

Figure 2-8 Display bottom, showing location

of EBL and VRM readouts

2.Operate the trackball to place the outside edge of the VRM on the inside edge of the target. The trackball must be operated within five seconds after pressing a [VRM] key, oth- erwise the corresponding VRM cannot be operated. Press the [VRM] key again to ad- just the VRM.

3.Check the VRM readout at the bottom right- hand corner of the display to find the range to the target.

4.To anchor the VRM, press the [VRM] key again.

To erase the VRM, press and hold down the corresponding [VRM] key about two seconds.

Range

6.0 NM

Range ring 2.0 interval

Target

VRM1

Cursor

VRM2

 

 

 

 

VRM1

 

 

VRM

 

range

Cursor range

 

4.0 NM

 

 

 

4.0 NM 3.0 NM

 

VRM2

 

 

 

 

 

 

range

Figure 2-9 Measuring range by the cursor

and VRM

Note: You can display the range readout of the VRM and cursor in nautical miles, statute miles or kilometers. For details see the next chapter.

2.15 Measuring the Bearing

There are two ways to measure the bearing to a target: by the cursor, and by the EBL (Electronic Bearing Line).

Measuring bearing by cursor

Operate the trackball to bisect the target with the cursor intersection. The bearing to the tar- get appears at the bottom of the display.

Measuring by EBL

1.Press the [EBL 1] or [EBL 2] key.

2.Operate the trackball to bisect the target with the EBL.

The trackball must be operated within five seconds after pressing an [EBL] key, other- wise the corresponding EBL cannot be oper- ated. Press the [EBL] key again to adjust the EBL.

3.Check the EBL readout at the bottom left- hand corner of the display to find the bear- ing to the target.

4.To anchor the EBL, press the corresponding [EBL] key again.

To erase the EBL and its readout, press and hold down the corresponding [EBL] key about two seconds.

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Furuno FR-7252, FR-7112, FR-7062 manual Measuring the Range, Measuring the Bearing