While many of the lessons of war are timeless, tactics do change as technology changes. Consider
the following observations and logic chain.
- With the existence of hundred/thousand mile cruise missiles,
multi-thousand mile ballistic missiles, supersonic aircraft and missiles, 50
mile torpedoes, SSGNs, etc., any ship that is spotted can be killed and fairly
quickly, from a distance.
- Given SIGINT, radar warning receivers, direction finders,
and all manner of electromagnetic sensing devices, any ship that emits,
intentionally or unintentionally, can be spotted.
- Hence, to be spotted is to be sunk.
- The obvious conclusion is don’t get spotted!
- The obvious way to reduce the chance of being spotted is to
emit nothing. No active radar. No unshielded electronic devices. No signals.
Emit nothing for an enemy to pick up.
Of course, with today’s ship designs, emitting nothing is,
potentially, another definition of being blind and a ship that is blind is
going to stumble into trouble.
The job of a naval force is to find the enemy. How can that be accomplished without active
emissions?
This is where we begin to see that we need a paradigm shift
away from active detection systems and toward passive systems. This doesn’t mean tacking a single
electro-optical (EO) sensor on the superstructure somewhere and glancing at it
occasionally, as is done today. Instead,
it means designing an entire ship around passive sensing as its main sensor
system. We need a passive warship
design. Let’s look a bit closer at this concept.
The Passive
Warship
The passive warship begins with a maximum stealth design
which includes not just radar stealth but infrared, acoustic, optical, electromagnetic,
and wake stealth. Once we have a ship
that is as stealthy as possible we can begin designing its sensing system. We want a maximum stealth ship design
combined with primarily passive sensing – a ship that can’t be seen but can see
all around itself. The enemy can’t see
it but it can see the enemy.
Electro-optical – The F-14 Tomcat (and other aircraft
– no need to list them) had optical systems that were reportedly capable of
detecting bomber size aircraft out to a hundred miles or so. We have optical telescopes that can see
distant galaxies. Of course, those
telescopes are far too large to mount on a warship but with something in
between the F-14’s tiny camera and a giant observatory telescope we should be
able to easily see fighter size aircraft at hundreds of miles. Place several (not just one!) of these EO
sensors around the ship to provide 360 degree coverage with a huge amount of
overlap and redundancy to allow for battle damage and we have 360 degree, long
range, passive sensing that matches or exceeds what radar can provide. Remember that one major advantage of optical
systems is that they can easily detect stealth aircraft.
What makes this approach viable is accompanying software
that can monitor the optical images continuously and detect the faintest of
possible targets – something that a human would fail to do simply due to visual
fatigue.
Of course, optical sensing is vulnerable to interference and
degradation from weather, smoke, and other effects. Thus, we need additional passive sensing to
supplement and complement optical sensing.
Infrared – Take the preceding EO concept and
duplicate it with IR sensors. Picture
aircraft infrared search and track (IRST) pods, scaled up for much greater
sensitivity and range, placed all around the ship to, again, provide 360 degree
coverage with overlap and redundancy. IR
sensing nicely supplements and complements optical sensing.
SIGINT – Signal intercept sensors provide passive
detection of enemy electronic signals and communications. These
signals might be fire control comms, voice comms, data communications traffic,
missile networking comms, helicopter traffic control comms, or any other type
of signal. Given the ability of many
signal types to travel beyond the horizon – and thus be detected over the
horizon – SIGINT can provide very long range detection.
UAVs – Not only do we want our passive warship to
have the preceding capabilities but we need to extend the ship’s sensor
reach/range using small, cheap reconnaissance UAVs equipped with passive
sensors. These UAVs can be employed
continuously for area recon, specifically for target confirmation or intense
monitoring of a specific area, or sporadically so as not give even a hint of
the host ship’s presence.
Fire Control – The final step is to tie the passive
sensor systems into the ship’s fire control.
Thus, passive sensors become the primary fire control and the ship never
needs to radiate, even while defending against an attack. Of course, if the ship is being attacked,
it’s already been spotted and it’s no longer necessary to remain passive. Active radar can be used at that point
although it would still be preferable to avoid active systems thereby
eliminating the enemy’s use of radar homing targeting.
There are already purely passive fire control systems throughout the world's militaries so this isn't something radically new.
An alternative fire control scheme might be a mixed passive/active scheme which coordinates passive
and active sensing so that tracking is passive and, at the last moment, active
sensors (radar) activate for weapon guidance. This would not, however, be the preferred approach.
Discussion
From the preceding, we can envision a passive warship at the
center of a 360 degree spherical ‘eye’ made up of dozens of optical, infrared, and
signal sensors. The sphere would extend
from the horizon to hundreds of miles for elevated targets. UAVs would further extend the monitored area.
The complementary systems would mitigate the negative
effects of weather and whatnot. What one
system fails to detect, another will.
Of particular note is the ability of passive systems to
detect stealth aircraft with ease. A
properly designed passive system almost renders radar stealth useless.
As noted, a passive fire control eliminates the enemy’s ability
to use radar homing weapons.
We see, then, that a purely passive warship system has a lot
going for it.
Radar would still be provided on our passive warship as
there may be occasions to use it but there would be no need for high end, Aegis
type systems. A simple TRS-4D type radar
for horizon ranges would be sufficient.
While the passive system is a rock solid concept, there are
some unknowns that would need to be tested.
For example, can passive sensors provide sufficient weapon
guidance? What size sensors do we need?
We need to set up a passive test ship and determine whether
we can detect, track, and fire control purely passively with sufficient
effectiveness. If we can’t, we need to
find out where the limitations are and work to eliminate them. We need to find out what the practical
detection ranges are for various size/shape targets and flight profiles. And so on.
Technology has changed and that demands a change in
tactics. Unfortunately, the Navy is
anchored in the past. We’re producing
Burkes that are based on technology and tactics that are several decades out of
date and hopelessly obsolete. Our latest
combat ship, the Constellation class, was obsolete before the first one was
even laid down. We are mired in the
past. It’s long past time for a paradigm
shift in warship design.
