October 2000 Newsletter - Naval Postgraduate School

MISSILE DEFENSE RESEARCH, continued from page 3
sary has any capability to strike targets in the U. S. with
nuclear missiles, U. S. actions toward that adversary will be
different than they would be towards a comparable nonnuclear
state. Research is continuing into the degree to
which deployment of National Missile Defense systems of
varying degrees of ABM treaty compliance would affect this
vulnerability, if at all. In the tactical sense, the technical
capability exists (even if actual systems are not yet deployed)
to target ships at sea with long-range ballistic missiles. Theater
missile defense developments have concentrated first on
shorter-range (SCUD-like) missiles. Even the most ambitious
theater defense systems are limited (by the ABM Treaty) in
the kinds of missiles they can engage. Research in this area is
focusing on the potential mismatch between projected
defensive capabilities and potential offensive capabilities and
on how this mismatch might be affected by proposed changes
to relevant treaties.
The Total Ship System Engineering (TSSE) Program under
the leadership of Professor Charles Calvano, Department of
Mechanical Engineering, and Robert Harney is a formal
partner in the Capabilities of the Navy After Next (CNAN)
Study funded jointly by DARPA and the Naval Warfare
Development Command. During the six-month long
capstone design project, the TSSE student team is investigating
the problem of access assurance and defining (in a
detailed conceptual design) a new class of small, versatile
surface combatants for facilitating access in a network-centric
environment. It is envisioned that the survivable, yet expendable
“boats” would deploy networks of sensors and weapons
throughout the adversary’s access denial zone. Once in place,
these assets would ultimately be used to negate the denial
systems. One component of the adversary’s denial strategy
may well involve the use of terminally guided, longer-range
ballistic missiles against our power projection forces once they
have entered the denial zone. As a consequence, CNAN is
considering the problems and benefits associated with deploying
freestanding, canisterized, TBMD assets such as SM-3
missiles deep into the access denial zone. Such forward
placement could significantly improve the force protection
capabilities of these missiles when compared to basing the
missiles on ships of the power projection forces. If the TSSE
team concludes that SM-3 forward basing is a significant
requirement, then such weapons would be included in the
overall mix of sensors and weapons that the CNAN combatants
would be required to deploy, and as such would influence
the design of those combatants. The TSSE student team is
RESEARCH OVERVIEW
expected to brief their results in late November 2000.
Detection and Tracking: Intercepting the TBM in the
Atmosphere
For the past three years, Associate Professor Robert G.
Hutchins and Professor Emeritus Hal Titus of the Department
of Electrical and Computer Engineering have been
engaged in TBMD studies to develop sensor fusion, data
association and tracking algorithms to provide the earliest
possible detection and tracking information to the interceptor
launch site. Hence, they have focused on intercepting the
TBM in the atmosphere on the way up. This work has been
funded by the Navy TENCAP Office.
The research objective is to develop sensor fusion, data
association and tracking algorithms, based on a variety of
sensor assets, which will provide the earliest possible detection
and tracking information for use in ballistic missile defense.
All possible sensors from strategic and theater platforms
(space, ship, aircraft, UAV) will be utilized to provide the
fastest missile intercept reaction time possible. The aim is to
bring to bear all assets available to cover a threatened launch
area and to fuse these observations as quickly as they are
obtained. This will allow the shooter to launch at the earliest
possible time. Rapid ballistic missile launch point prediction
is another research objective. Longer-term studies will assess,
via simulation, the feasibility of intercepting the ballistic
missile during ascent using aerodynamic missiles fired from
the surface and/or airborne platforms.
Research has focused on two types of sensors, space based
strategic sensors that would likely provide the first indication
of a missile launch, and the Aegis radar system as the most
likely system to take a hand-off from the strategic sensor to
track the TBM until final intercept, although the algorithms
developed would allow processing of a much wider variety of
sensor types. One issue explored here is how good the
initial velocity and acceleration measurements must be in
order for the surface-based radar system to take over the target
track with a minimum of transient behavior in the track. It
was found that prior information on missile velocity and
acceleration profiles are extremely helpful in track initiation
for the surface-based radar system. Hutchins and Titus have
advocated a modified Kalman-based tracking algorithm that
allows processing measurements from a wide variety of
sensors, provided a common coordinate system framework
can be maintained. Both polynomial backfit and Kalman-
--continued on page 5
NPS Research page 4
October 2000