1. The LONG-RANGE IDENTIFICATION AND TRACKING (LRIT) of ships was established
as an international system on 19 May 2006 by the International Maritime Organization (IMO) as
resolution MSC.202(81). This resolution amends chapter V of the International Convention for
the Safety of Life at Sea (SOLAS), regulation 19-1 and binds all governments which have
contracted to the IMO.
The LRIT regulation will apply to the following ship types engaged on international voyages:
All passenger ships including high-speed craft,
Cargo ships, including high-speed craft of 300 gross tonnage and above, and
Mobile offshore drilling units.
These ships must report their position to their flag administration at least four times a day. Most
vessels set their existing satellite communications systems to automatically make these reports.
Other contracting governments may request information about vessels in which they have a
legitimate interest under the regulation.
The LRIT system consists of the already installed (generally) ship borne satellite
communications equipment, communications service providers (CSPs), application service
providers (ASPs), LRIT data centers, the LRIT data distribution plan and the International LRIT
data exchange. Certain aspects of the performance of the LRIT system are reviewed or audited
by the LRIT coordinator acting on behalf of the IMO and its contracting governments.

2. A RADIO DIRECTION FINDER (RDF) is a device for finding the direction to a radio source. Due to low
frequency propagation characteristic to travel very long distances and "over the horizon", it makes a
particularly good navigation system for ships, small boats, and aircraft that might be some distance from
their destination (see Radio navigation). The distinct technology Range and Direction Finding was the
abbreviation used to describe the predecessor to radar.
World War II US Navy high frequency radio direction finder

3. INTRODUCTION TO SATELLITE BASED NAVIGATION SYSTEMS
Through the advancement of the science and technology the Satellite based
navigation
and positioning systems have become the most important technological trend in the
areas such as General surveillance, civil aviation control and air traffic management.
The older systems have not been developed expecting such a huge air traffic density
now existing. The example systems are,
Instrument landing system for landing aid
DVOR/DME system for navigation
Above systems were showed satisfactory performance even now but when the satellite
based systems prove their ability to work with these conditions precisely and effectively
the ICAO is considering to converge to that technology. The satellite based systems
have many advantages over the existing systems.
Satellite based systems achieve greater accuracies than most existing
technologies because the satellite signals are propagated independent of the
ground making the system less prone to ground derived errors.
Since there are several satellite based systems are available such as GPS (US)
GLONASS (USR) and GALILEO (Europe) all of these systems can be utilized to build a
single accurate system.
But there were several problems which causes this to be come into the field of operation
and finally ICAO decided to develop a system called GNSS( Global Navigation Satellite
System ) working on all the above systems. But for the civil aviation control the more
accuracy was required and it has to proven as accurate. The augmentations systems
are employed in the GNSS provide the needed accuracy by correcting the
measurements dynamically based on all the satellite systems existing and updating the
user. There are several variations of the above augmentation systems such as SBAS,
GBAS, ABAS and GRAS. This report concerns basically popular two of above popular

4. systems which are SBAS (Space Based Augmentation System) and GBAS (Ground
Based Augmentation System).
LANDING NAVIGATION (SATTELITE BASED)
LOCAL AREA AUGMENTATION SYSTEM – A GBAS SYSTEM

5. SONAR is an acronym for Sound Navigation And Ranging. It has been used and studied primarily for military
applications. It is used worldwide and uses sound propagation to navigate, communicate, or detect objects
underwater. It became important during WWI and WWII for detecting enemy submarines and vessels.
Oceanographers also make use of sonar technology in their line of work quite often. They can use this technology to
map out the ocean floor. One technique they use is the Multibeam Bathymetry (aka echo-sounder). An echo-sender
sends an acoustic pulse directly the seabed and the time it takes for the pulse to reach the bottom and come back to
the vessel determines the depth. The sound pulse is generated by a transducer that emits an acoustic pulse and then
“listens” for the return signal to determine the depth. Then return signal is recorded and converted to a depth
measurement by calculating the speed of sound in water. The speed of sound in the water is approximately 1500
m/s. This concept comes from the assumption that many beams are better than just one. With this concept a system
was developed by the Navy that allows for there to be many beams of sound to be sent out simultaneously as
opposed to just one to get a series of water depth readings along the line of a moving vessel. Instead of having one
transducer pointing straight down, the multibeam bathymetry systems has arrays of 12Hz transducers which can
sometimes number as high as 120 and are arranged in a precise geometric pattern. The sound these ships send out
can cover a distance of twice the depth of the water on either side of the ship. All the sound sent out of the ship
bounces off of the sea floor and return to the ship where computers use the data to construct a bathymetric map of
the sea floor

6. Speed measurement / protection modules - T401 provides current
output and a set point relay; T411 adds a five-digit display.

7. TRANSIT SATTELITE SYSTEM
A satellite navigation or sat nav system is a system of satellites that
provide autonomous geo-spatial positioning with global coverage. It
allows small electronic receivers to determine their location (longitude,
latitude, and altitude) to within a few metres using time signals
transmitted along a line-of-sight by radio from satellites. Receivers
calculate the precise time as well as position, which can be used as a
reference for scientific experiments. A satellite navigation system with
global coverage may be termed a global navigation satellite system or
GNSS.
The global coverage for each system is generally achieved by a
constellation of 20–30 Medium Earth Orbit (MEO) satellites spread
between several orbital planes. The actual systems vary, but use orbit
inclinations of gt;50° and orbital periods of roughly twelve hours
(height 20,000i km / 12,500 miles).

8. Early predecessors were the ground based DECCA, LORAN and
Omega radio navigation systems, which used terrestrial longwave
radio transmitters instead of satellites. These positioning systems
broadcast a radio pulse from a known master location, followed by
repeated pulses from a number of slave stations. The delay between
the reception and sending of the signal at the slaves was carefully
controlled, allowing the receivers to compare the delay between
reception and the delay between sending. From this the distance to
each of the slaves could be determined, providing a fix.
The first satellite navigation system was Transit, a system deployed by
the US military in the 1960s. Transit's operation was based on the
Doppler effect: the satellites traveled on well-known paths and
broadcast their signals on a well known frequency. The received
frequency will differ slightly from the broadcast frequency because of
the movement of the satellite with respect to the receiver. By
monitoring this frequency shift over a short time interval, the receiver
can determine its location to one side or the other of the satellite, and
several such measurements combined with a precise knowledge of
the satellite's orbit can fix a particular position.