Table of Contents
Advertisement
ROSS
For example, an ID can be the coordinated area's greatest, or smallest, longitude value expressed
in hundredths of a degree. If the largest eastward longitude value in the coordinate set is -42.57
(equivalent to 42.57W = 317.43E) it can be used as an id value of 31743. This method of
generating ID numbers would ensure uniqueness and give some meaning to the value.
5.16 Shoreline Override
Coordinated Areas support a shoreline override value. If the shoreline override value is non-
zero, then the Transmit Flag is not used to control modem transmitter if the vessel is inside
the Coordinated Area. The shoreline threshold detection controls the modem transmission
while the vessel is inside a coordinated area.
5.17 Nested Coordinated Areas
Example Figure 9 shows nested coordinated areas, where the multiple coordinated areas have
overlapping polygons. The default (global) shoreline value is 100Km as shown by the orange
line. The large coordinated area, (id 31114) in green has a shoreline override set to 5.0 while the
smaller nested coordinated area (id 31743) has it's transmit flag disabled with a shoreline
override of 0.0. A vessel inside area, (31114), and not in area (31743), would be permitted to
transmit until is crosses the 5Km shoreline threshold. If the vessel is inside area (31743), no
transmission is allowed. Area (31743) is effectively a blocked transmission zone.
When creating coordinated areas that are nested, or overlap one another, the order of
declaration is critical. ROSS performs a sequential search to check vessel position against the
coordinated area polygons. The first coordinated polygon that contains the position is used to test
transmission mode. The general guideline is to declare the inner most polygons ahead of the
outer most polygons.
Comtech EF Data, Vipersat Products
200Km
Figure 9: Example of Coordinated Areas
Default Shoreline Value 100.0Km, when a vessel crosses this
boundary, ROSS will mute its modem transmitter unless a
coordinated area overrides the Shoreline threshold.
Coordinated Area 31114, shoreline override 5.0 Km, transmit
flag ignored. If a vessel is inside this zone, it will be allowed to
transmit up 5 Km from the coastal shoreline.
Coordinated Area 31114, shoreline override 5.0 Km boundary.
Coordinated Area 31743, shoreline override 0.0 Km, transmit
flag disabled. Any vessel inside this coordinated area is not
allowed to transmit. This is a blocked transmission zone.
MN/13070
Page 62 of 87
Advertisement
Table of Contents
