ABSTRACT
Master and secondary transmitting stations are
located at strategic places to provide the required
geometry for obtaining navigation information.
Transmitter towers are typically 700-1300 feet
high and radiate between 400 and 1600 W of
power. The master and secondary stations are
formed in groups known as chains as discussed
earlier. Baseline distances vary from chain to
chain since many stations are located on islands
to provide oceanic coverage; distances of between
175 and 1000 nm are typical. The majority of
these chains are in the USA and Canada; other
chains are located in Russia, the northern Pacific,
Europe, Asia and the Middle East. The master
stations are identified as ‘M’ and the secondary
stations are identified from the series ‘W, X, Y
and Z’. The US Coast Guard (USCG) provides
full details of each chain, together with an on-line
handbook containing very useful data and
information relating to Loran; details can be
found on their website www.navcen.usg.gov. The
USCG introduced Loran-C into Europe, the
system was transferred to the host nations in
Table 14.1 provides a list of currently available
Loran-C chains, together with a summary of how
many secondary stations are associated with the
master. Table 14.2 provides details for the
Northwest Pacific chain; this comprises stations
on the Japanese mainland and a number of islands
in the Pacific. Figure 14.7 gives an illustration of
the area of coverage for this chain.
