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decision, this information is incorporated in the
decision process. For instance when the operational
alert state changes from peace to tension or a target
violates a self-defence safety zone this has to be
considered for the identity decision. For all these
cases a set of dedicated loss tables has to be
provided, which contain modified loss values
regarding operational facts and target relevant
criteria.
3 NON-STANDARDISED
SOURCE TYPES FOR
IDENTIFICATION AND
CLASSIFICATION
The following section describes our solution for
some additional sources and sensors which were not
yet covered by the identification standard. Hence we
enhanced the standard and introduced capabilities
like Automatic Identification System (AIS),
Automatic Target Recognition (ATR) and Ground
Moving Target Indicator (GMTI) Radar. For some
of these the implemented solution is presented in the
following sections.
3.1 Automatic Identification System
The Automatic Identification System (AIS) is
originally a radio-based collision avoidance system
for ships. AIS has the main requirements to
▪ Support the avoidance of collisions by enabling
an efficient navigation of vessels;
▪ Support the protection of the environment by
providing information about the ship’s cargo;
▪ Actively support Vessel Traffic Systems (VTS)
by providing static, dynamic and voyage data.
Besides that port authorities use AIS to warn ships
about hazards, low tides and shoals that are
commonly found at sea. In open sea AIS-enabled
distress beacons are used to signal and locate men
who have fallen overboard (Balduzzi, 2014).
Several state-of-the-art surveillance satellites are
now equipped with AIS (Høye, 2007), thus the fused
information from dual sensors Radar and AIS
contributes to global maritime surveillance. But also
naval ships like corvettes and frigates are going to
exploit received AIS data for the improvement of the
maritime picture and tactical situation in real-time.
The information extracted from AIS radio broadcast
data includes:
▪ Static ship data: Maritime Mobile Service
Identity (MMSI), i.e. the vessels unique
identification number, International Maritime
Organization (IMO) ship identification number,
radio call sign, name of the vessel, type of ship;
▪ Dynamic ship data: navigation status, position of
the vessel, time of position, course over ground,
speed over ground, true heading, rate of turn;
▪ Further voyage data: current maximum draught
of ship, hazardous cargo, destination, estimated
time of arrival (ETA) at destination.
In a first step the received positional data of a vessel
are used for the association of the AIS data with
existing system tracks, which is part of the source
data association. If no matching system track is
available a new AIS based system track will be
initiated and the track is updated with the AIS
position data.
For the evaluation of AIS data for military target
purposes it is important to recognize that AIS
message content can be spoofed easily, so that the
manipulated result of the data association process or
from the information exploitation may be erroneous.
Besides the intentional manipulation also any kinds
of intentional and unintentional interference of the
AIS signals or the improper setup of AIS devices
may cause problems in the evaluation.
The AIS is a civilian system, hence no primary
military information is transmitted by default. For
military purposes also dedicated variants (NATO
STANAG 4668 WARSHIP - AUTOMATIC
IDENTIFICATION SYSTEM (W-AIS) and NATO
STANAG 4669 - AUTOMATIC
IDENTIFICATION SYSTEM (AIS) ON
WARSHIPS) exists, which are not handled here in
this paper. In order to use the civilian AIS data for
military identification and classification purposes a
further processing is necessary. In the optimal case a
database providing military and intelligence
information is available, such that the received AIS
data can be compared with it and the stored
(military) information can be retrieved to support the
tactical interpretation. The database content provides
information like ship type, specific type, platform
class and platform name, allegiance, civil/military
information and of course data like sensor
equipment, weapon systems and further tactical
intelligence information.
But usually on board of a ship this intelligence
database is not available and such a more pragmatic
solution was additionally necessary. In this case the
broadcasted MMSI number is exploited, because the
MMSI number uniquely identifies a vessel. The
MMSI is not an identity in the military sense, where
a distinction between civil and military objects and
Bayesian Multi-sensor Data Fusion for Target Identification - Applications in Naval and Ground based Command and Control Systems
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