Page 192 - Technology Roadmap Transportation

TECHNOLOGY VISION 2035

where technical innovations have over the years transmitters for positioning of vessels. These
yielded newer, more precise ways to chart one’s positioning systems broadcast a radio pulse
course across the high seas, celestial navigation from a known “Master” location, followed
using rudiments of astronomy (the positions by repeated pulses from a number of slave
and apparent motions of the sun and the stars) stations. The delay between the reception and
still constitutes the basis of many of the newer sending of the signal at the slaves is carefully
techniques of modern navigation and remains controlled, allowing the receivers to compare
the one, unfailing option for navigators. Modern the delay between reception and sending.
navigation, in a globally integrated transportation From this the distance-to-each of the slaves
system, requires fulfilling four basic objectives in can be determined, providing a fix for the
each voyage from start to finish: vessel.

LORAN (Long Range Navigation) is one
such system still in use, which enables ships to
Planning, recording
and controlling the determine their positions and speed from low
movement of the frequency radio signals transmitted by fixed
ship i.e. staying on land based radio beacons, using a receiver unit.
course while moving Minimizing fuel The most recent version of LORAN in use is
from one place to consumption
another LORAN – C which operates in the low frequency
portion of the radio spectrum from 90 to 110
kHz. In recent decade, LORAN use has seen steep
decline, with the satellite based navigation system
Ensuring safe and
efficient operations of being the primary replacement. However, there
Confirming to the ship at sea and have been attempts to enhance and re-popularize
an established avoiding accidents LORAN mainly to serve as a backup and land
timetable such as collision,
grounding and based alternative to other satellite base navigation
stranding etc systems.
4.3.2 Satellite Navigation (SATNAV) System
BASIC OBJECTIVES OF MODERN NAVIGATION
Satellite Navigation system is a system of satellites
that provide autonomous geo-spatial positioning
4.3.1 Current navigation technologies of objects. It allows small electronic receivers to
One of the fundamental trends in the maritime determine their location (longitude, latitude and
industry currently has been an increasing reliance altitude) to within a few meters using time signals
on electro-technical, electronic, electro-acoustic, transmitted along a line-of-sight by radio from
electro-optical and data-processing techniques. In satellites.
order to help navigators achieve the objectives
of maritime navigation in a safe manner. New A satellite navigation system with global coverage
stringent maritime regulations, complexity of may be termed as a Global Navigation Satellite
maritime traffic together with availability of System (GNSS). As of now, only the United
modern technologies have motivated ship owners States of America’s NAVSTAR Global Positioning
to install newer and most modern nautical marine System (GPS) and the Russian GLONASS are
instruments and systems onto the navigating fully globally operational GNSS. Global coverage
bridge of merchant ships for navigational safety. for each system is generally achieved by a satellite
Technologies that have been utilized for safe constellation of 20~30 medium-earth-orbit
navigation are discussed below: satellites spread between several orbit planes.

1. Marine radars: These are x-band or s-band The Indian Regional Navigational Satellite System
radars to provide bearing and distance of ships (IRNSS), being developed by Indian Space
and land targets in vicinity from own ship for Research Organization (ISRO) under the total
collision avoidance and safe navigation at sea. control of the Government of India, is going to
Now a days, radars are rarely used alone on be an autonomous regional satellite navigation
board merchant ships. They are integrated into system. It will consist of a constellation of seven
a full system of navigation bridge equipment. navigational satellites. All the seven satellites will be
2. Ground based radio navigation systems: placed in Geostationary Orbits to have a larger
These systems use terrestrial long wave radio signal footprint and lower number of satellites to

190 WATERWAYS