SAM Electronics GmbH NG3028X25KW Manual Do Utilizador
ED 3038 G 232 / 01 (2002-06)
Operating Instructions
6 Bearing and Range
6.4 Operating the VRM and the EBL Jointly
b_r1_e24.fm / 21.06.02
65
RADARPILOT / CHARTRADAR
Displaying the Relative Bearing
PPI Orientation North-Up and Course-Up:
The values displayed are true bearings. This fact is indicated in the
middle EBL-area by the letter T (= true). For as long as the DO key
is kept pressed in this area, the relative bearing is displayed (indi-
cated by R = relative).
The values displayed are true bearings. This fact is indicated in the
middle EBL-area by the letter T (= true). For as long as the DO key
is kept pressed in this area, the relative bearing is displayed (indi-
cated by R = relative).
☞
If the compass signal fails, the display is automatically switched over to relative bearing (R).
PPI Orientation Head-Up:
The values displayed are relative bearings. For as long as the DO key is kept pressed in this area, the
true bearing is displayed.
The values displayed are relative bearings. For as long as the DO key is kept pressed in this area, the
true bearing is displayed.
USEFUL INFORMATIONS
Latitude-Dependent Errors in the Display of the EBL
With the type of projection used for the longitude/latitude grid in the radar, the parallels of latitude become
more strongly curved with increasing latitude, while the meridians converge increasingly with increasing
distance from the equator (i.e. the direction of a meridian at the edge of the PPI is not 0
more strongly curved with increasing latitude, while the meridians converge increasingly with increasing
distance from the equator (i.e. the direction of a meridian at the edge of the PPI is not 0
° - 180° but might
be 358
° - 182°); in other words, their directions no longer correspond to the degree scale at the edge of
the PPI.
In contrast to this, the EBL is always displayed as a straight line; its bearing displayed as an EBL value
has an error.
has an error.
The following table shows the maximum errors for the various latitudes and range settings.
6.4
Operating the VRM and the EBL Jointly
If the EBL origin is set to CENTER, then after clicking on the point of
intersection of VRM1 and EBL1 or of VRM2 and EBL2, both
elements are moved jointly.
intersection of VRM1 and EBL1 or of VRM2 and EBL2, both
elements are moved jointly.
Measuring the Range and Bearing between Two Objects
If the EBL1 origin is set to FIX ABS or FIX REL, a marker is
displayed on EBL1 such that the distance of this marker from the
EBL1 origin is equal to the value of VRM1. If you click on this marker,
both VRM1 and EBL1 are changed by means of the cursor.
displayed on EBL1 such that the distance of this marker from the
EBL1 origin is equal to the value of VRM1. If you click on this marker,
both VRM1 and EBL1 are changed by means of the cursor.
The same applies to EBL2 and VRM2.
☞
By means of this procedure, the range and bearing between two objects can be measured: set the
EBL origin on object 1 and drag the marker to object 2.
EBL origin on object 1 and drag the marker to object 2.
Distance of EBL from
own ship
Geographical latitude
20 °
40 °
60 °
80 °
10 NM
< 0.1 °
0.1 °
0.3 °
0.9 °
20 NM
0.1 °
0.3 °
0.6 °
1.9 °
40 NM
0.2 °
0.5 °
1.2 °
3.8 °
60 NM
0.4 °
0.8 °
1.7 °
5.7 °
80 NM
0.5 °
1.1 °
2.3 °
7.5 °
DO
CENTER
1
T
122.7 °
CENTER
1
R
122.7 °
EBL
CENTER
1
T
CENTER
2
T
122.7 °
OFF
VRM
2
OFF
1 2.00 NM