IEEE Geoscience and Remote Sensing Magazine - June 2019 - 108

to defend NATO allies against all ranges of enemy ballistic missiles in three phases of flight: boost, midcourse, and
end phase. Each phase presents different opportunities and
problems for ballistic missile defenses. From an operational
perspective, the BMDS is currently deployed only as an endphase defense asset (i.e., the terminal high-altitude-area defense, Patriot, and Standard missiles), although intercepting
the payload before it builds up sufficient speed to reach its
target is preferable (i.e., during the boost phase). Technically, defense in this phase is challenging because the intercept
timelines are very short (i.e., 1 and 5 min, respectively [39]).
On the other hand, interception during the boost phase is
encouraging because rocket boosters are relatively easy to
detect and track, they are somewhat vulnerable due to the
large axial loads on a missile under powered flight, and the
entire payload may be destroyed in a single shot [40]. Boostphase intercept system designs typically use an architecture
that integrates an acquisition- and tracking-based radar and
IR sensors. Although initial detection and tracking can be
separately obtained, fusion capabilities create a robust architecture that eliminates false alarms [41].
Passive IR systems can detect missile plumes with reasonable accuracy from a distance of thousands of kilometers and so can detect ballistic missile launches from highEarth, geosynchronous, airborne, or ground payloads [40].

with limited success. One reason that military detectors are
operated in the visible NIR (VNIR) and SWIR parts of the
electromagnetic spectrum is related to the discrimination
of camouflaged materials. Here, the goal is to achieve very
high spectral resolution analysis of the scene, even if it is of
relatively lower spatial resolution [36, p. 4].
Figure 8 presents an example of a camouflaged vehicle
in an HSI scene. The spectral plot does not reveal significant
differences between the target and its background; however, a 3D plot of three selected continuous bands allows for
discrimination of the camouflaged target.
Based on our knowledge, advanced camouflage materials are able to thermally conceal a target in the midwave
IR (MWIR) and LWIR parts of the spectrum. However,
they cannot replicate the emission features of abundant
minerals in the continental crust (i.e., quartz, silicates, or
gypsum). Thus, a hyperspectral detector, which operates
in the reflective and thermal wavelengths, is an outstanding countercountermeasure against any available camouflaged materials.
EARLY WARNING FOR LONG-RANGE
MISSILES AND SPACE SURVEILLANCE
The Ballistic Missile Defense System (BMDS) is an integrated architecture of land, sea, air, and space assets designed

50
100
150
200
250

250

300

200
150

350

100
50
0
300

400
450

200

500

100

550
10

(a)

150
50 100

0 0

200

250

(b)

250

PLOT SPECTRUM

200
150
100
50
0

450

500

550

600

650
700
(c)

750

800

850

900

FIGURE 8. (a) An HSI scene of a camouflaged vehicle in the operating system, (b) a 3D representation of selected bands, and (c) a plotted

spectrum of pixels in selected areas [38].
108

IEEE GEOSCIENCE AND REMOTE SENSING MAGAZINE

JUNE 2019

IEEE Geoscience and Remote Sensing Magazine - June 2019

Table of Contents for the Digital Edition of IEEE Geoscience and Remote Sensing Magazine - June 2019