LORAN (Long Range Navigation)

LORAN (Long Range Navigation) The
latest system known as LORAN-C .This
system will be discontinued due to
cost not effective. The US will continue
to operate the LORAN-C system
beyond the previously planned December 31, 2000. The termination
date is continuing to evaluate the long
term need for continuation of the
system. User will be given reasonable
notice so that they will have the
opportunity to transfer to alternative navigation aids. At this time we will
talking about this system a little
because they might keep this system
as a back up system.
OPERATION
LORAN is a net work of land based radio transmitters and was
developed to provide an accurate
system for long range navigation.

LORAN Stations Operations are
organized into sub-groups of four to
six stations called " CHAIN ".One station in the Chain is designated the "
MASTER " and others are called "
SECONDARY " or " SLAVE " Stations. The theory is to calculate the time
between reception of the signals from
the MASTER and SLAVE stations, which
are emitted at different frequencies , at
low or very low bands 90kHz - 110
kHz. in pulse group and has power of 400 - 1600 kilowatts. The master
station emits its own signal first, when
that signals reach the slave station , it
emits its own signal after a
predetermined delay. When the master
station's signal reaches the aircraft , its Navigation system counts the time
until the slave station's signal arrives.
Your position is found as the
intersection of the line of two LORAN
stations.
LORAN UNIT
• SIGNAL PROCESSOR
• NAVIGATION COMPUTER
• CONTROL and DISPLAY
Signal Processor receives the signals and measures the difference between
the time of arrival of each secondary
station pulsegroup and the master
station pulse group. The time
difference is depend on the location of
the receiver on the aircraft in relation to the three or more transmitters.Each
time difference value is measured to a
precision of about 0.1 microseconds.
Navigation Computer converts time
difference values to location
corresponding latitude and longitude.
Control and Display
• The functions of the LORAN UNIT is: Preset Position in Latitude- Longitude and/or relative to a
destination, waypoint or check point.
• Bearing and distance to your destination
• Ground speed and estimated time enroute.
• Course Deviation Indicator.
• Storage in memory of airports.add- on programable and updatable
database
• Continuous computation of bearing and distances to the nearest airports.
computation of wind direction and
velocity.
• Add-on such as fuel flow analyzers to estimate fuel need to reach
destination.etc.