Dsc Call Menu; Geographic Area Computation - Sailor System 5000 MF/HF User Manual

4.11

DSC call menu

MENU
1. DSC CALL 1. COAST STATION 1. WITH PHONE NO MMSI
2. SHIP
3. AREA
4. DISTRESS
5. INDIVIDUAL
6. GROUP
7. TEST CALL
*) Nature of distress:
FIRE, EXPLOSION, FLOODING, COLLISION, GROUNDING, DANGER OF CAPSIZING, SINKING, DISABLED AND ADRIFT,
UNDESIGNATED (default), ABANDONING SHIP, PIRACY, MAN OVERBOARD, EPIRB EMISSION (Distress Relay only)
4.12

Geographic Area Computation

When transmitting a geographical area call, the user is requested to enter the position of the
ship (x,y) and the radius of interest r. This information is transformed to a square with a
corner point and the length of its sides
transmitted over the air. See the figure below for an illustration of the relation between the
user input (the white circle) and the information transmitted over the air (the grey square).
The center point is the position of the ship measured in degrees and minutes, whereas the
radius of interest is given in nautical miles.
The corner point of the square and the length of its sides is given in degrees. Note that these
values are rounded to degrees, and due to the requirement that the square shall include the
entire circle; this will result in a slightly larger area than defined by the user input.
Also note that special handling is required when close to the poles. If the latitude of the
corner point is transformed to a value greater that 90° then
the square is reduced correspondingly. If the length of the square
then is set to 90°.
30
MMSI
2. WITHOUT NO
MMSI
POS CATEGORY
RADIUS
1. ALERT MODE
2. RELAY 1. COAST STATION MMSI
2. SHIP
3. AREA
MMSI CATEGORY
MMSI MODE
1. SHIP TEST CALL MMSI
2. COAST STATION MMSI
TEST CALL
Phone no MODE
MODE
MODE
MODE Working
freq
Nature of POS
distress *
Ship in
MMSI distress
POS
RADIUS
MODE FREQUENCY DSC freq
POSITION
Working freq DSC freq
DSC freq
DSC freq
and . Finally the DSC message is
is set to 90° and the length of
DSC freq
DSC freq
Working freq DSC freq
DSC freq
DSC freq
MODE Nature of POS
distress *
is greater than 90°
0735