Navigation
Normal space navigation is carried out with the aid of System
Navigation Beacons, which provide precise 4-D position fixes to
users. Most System Navigation Beacons use some form of
spread-spectrum technology to reduce the power required to make a
broadcast signal heard across an entire solar system, and to avoid
drowning out nearby radio traffic from the power of the signal.
Since a spread-spectrum signal is weaker than background noise at
the receiver, the receiver has to "know" the Pseudo-Random Noise
(PRN) code imposed on the carrier signal to identify signal amid
background noise. The Imperium has a set of standard PRNs used
Imperium-wide for normal use. Military navigation systems have
their own secret PRNs with encrypted Nav signals.
In a war zone, the Imperial Navy (or local authority, if
non-Imperial) will shut down the civilian system to impair enemy
navigation insystem. This is one reason, in addition to hazards
from combatants, that War Zone systems are made Amber zones or
occasionally Red Zones. [BTW, this is based on our (1992 Real
World) GPS and Russia's GLONASS systems].
Grade of starport usually implies comparable grade of
navigation systems. A class E starport may have one beacon at the
starport (which is useful for finding the starport, and not much
else), whereas a class A starport mainworld has a full
constellation of navigation beacons around every major body in the
system (which makes deep space navigation a trivial exercise).
Interstellar jumps make use of a published ephemeris for a
system, listing all the celestial bodies and major installations,
and their orbital statistics such that their positions can be
calculated at any given time. With an accurate ephemeris and
competent navigation, a merchant ship or battleship can jump
precisely to the 100-diameter limit of their destination world.
Without an accurate ephemeris, it is usually necessary to jump
into the outer system, above the plane of the ecliptic (to avoid
debris and traffic), and calculate one's own ephemeris from
collected sensor data.
Many worlds with less-than-trusting rulers issue falsified
ephemerii. The fixes provided by their System Navigation Beacons
compensate for this falsification, so it has no effect in ordinary
use. During Emergencies (war, raids, etc.), the Beacons can be
shut down, and the falsified ephemeris makes it harder (tho far
from impossible) to get an accurate jump fix, and, more important,
makes it nearly impossible to launch a ballistic strike from an
extreme distance (i.e., throw asteroids at the planet from beyond
detection range.) The ephemerii used by the Imperial Navy are
either *UNCONFIRMED* (the public, possibly falsified ephemerii
issued to civilians) or *CONFIRMED* (true, usually classified,
ephemerii that have been verified true by Scout Service
surveying.)
-- Cynthia Higginbotham
"Q: What is the difference between the BATF and the Gestapo?"
"A: BATF agents speak English."