Government Security News

coverage of AIS network by adding
receivers on offshore assets
such as offshore platforms and
workboats in high-density areas
such as the Gulf of Mexico. However,
while expanding visibility in
those areas, the offshore receivers
still did not address the challenge
of tracking ships at sea.
In 2008, the first commercial
AIS receivers were launched
into orbit as a satellite payload.
The initial satellite launches
were largely experimental, and
demonstrated that it indeed was
possible to detect AIS signals of
vessels in open water from an
orbiting satellite. This kicked off
the era of satellite AIS, as several
commercial operators began offering
satellite AIS services to
both government and commercial
clients.
From a wheelhouse perspective,
satellite AIS provides
minimal value. However, from
a shore-based business perspective,
satellite AIS provides many
benefits, including:
• Ability to track any AIStransmitting
vessel globally
• Ability to support searchand-rescue
and anti-piracy measures
by increasing the visibility
of ships at sea by first responders
and security personnel
• Ability to provide market
intelligence through aggregating
data across many vessels and
regions to answer business questions
• Ability to support compliance
and law enforcement activities
The above benefits are compelling.
However, it is also important
to recognize the limitations
of satellite AIS
Much lower reporting frequency.
While terrestrial AIS can
report vessel positions in nearreal-time
(with multiple updates
each minute), satellite AIS has
significantly higher latency and
lower frequency of reporting.
Current satellite AIS service providers
typically provide position
updates on specific vessels only
a few times each day. While this
lower frequency of reporting still
provides compelling value to
track the progress of ships at sea,
it does not allow for many of the
advanced alerting and reporting
features that are available with
terrestrial AIS.
Limited detection of vessels.
The ability to detect AIS signals
from space is currently an imperfect
“art”. Electromagnetic interference
(particularly in dense
areas) often limits the ability to
detect vessels in congested areas,
even when vessels are transmitting
their AIS signal.
Cost. It is expensive to
launch a satellite, and the commercial
satellite operators need
to recoup that investment. As
such, satellite AIS typically carries
significantly higher licensing
fees than terrestrial-only AIS
providers.
PortVision has been providing
satellite AIS to customers
since the first satellites were
launched over 5 years ago. We
continue to maintain a leadership
position in aggregating terrestrial,
offshore, and satellite
AIS to provide the highest-value
offering to our users. Combined,
we process over 50 million ship
location reports per day from all
AIS sources in our network. And
satellite AIS data plays an important
role for many of our users,
particularly those users who require
in-transit visibility to ships
around the world.
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