Remember the scene in Patriot Games where the protagonist
and his CIA colleagues watch real-time infrared images of helicopter-borne
special ops warriors neutralizing terrorists in a remote Libyan desert? That
might have been the stuff of Hollywood then, but it's reality now.
Thanks to Salt Lake City-based L-3 Communications' Tactical
Common Data Link (TCDL), commanders in the field, on ships or in offices
thousands of miles away can monitor streaming live surveillance video, allowing
them to focus on a firefight, potential target or anything else on the ground.
These and other imaging capabilities are especially
important in Afghanistan, where enemy compounds are often surrounded by high
walls, and where the country's mountains and deep valleys make situational
awareness an even tougher job for ground forces.
Initially independent of plans for the TDCL, the Navy
decided to modernize its Lockheed Martin P-3 Orion aircraft with an
Anti-Surface Warfare Improvement Program (AIP), a key component of
network-centric warfare.
The modernization involves installing high-resolution,
synthetic-aperture radar and electro-optic and infrared sensors to dramatically
increase the ability to see over land. AIP has become the platform of choice to
provide intelligence, surveillance and reconnaissance for land- and sea-based
operational commanders in the Afghan conflict.
Although TCDL is not currently part of the defined AIP, TCDL
units have been placed as prototypes on AIP aircraft; and their tests have been
so successful that TCDL is now a candidate for AIP, said Captain George Hill,
program manager for Naval Air Systems Command's Maritime Patrol Aircraft
Program (PMA-290).
"TCDL allows us to send a wide variety of data off the
aircraft at a high data rate," said Hill. "Perhaps the most tactically
significant capability is that of sending streaming video from the
electro-optic or infrared sensors on the airplane to a ground station which is
within line of sight."
Though underground Taliban and Al Qaeda fighters are
invisible to the naked eye, TDCL-equipped P-3s, thousands of feet in the air,
can detect them and deliver ordnance, if necessary.
The newly installed TCDL has many advantages. From the
secure-voice portion of the link, surface commanders can request visual
verification of objects of interest as the planes pass over them. With the file
transfer capability, digital images and files can be sent and received at air
or ground stations. American and allied troops on the ground in contact with a
TCDL-equipped P-3 can respond to that information almost immediately. The
"sensor-to-shooter time" - the time from the moment a target is located to the
moment it can be fired at - has been reduced from hours to minutes.
"The P-3C Orion with AIP will play a key role in ensuring battlespace
dominance in the littorals of the 21st century," Vice Admiral John B. Nathman,
commander of Naval Air Forces, told the Senate Armed Services Committee. "At
any given time we have squadrons deployed in every major region of the world.
From the Caribbean to Keflavik, from Signonella to Bahrain and Masirah in the
Gulf, from the middle of the Indian Ocean on the island of Diego Garcia to Japan,
our P-3s are providing critical surveillance, anti-surface warfare and undersea
warfare to our unified CINCs [commanders in chief]."
New eyes and ears for an old
workhorse
At one point during the last decade, the P-3 aircraft looked
as if it was nearing the end of its operational life. But instead of replacing
one type with another, the Navy embarked on an ambitious upgrade of the old
workhorse.
The upgrade set a new baseline for configuring advanced
sensors and weapons, increasing interoperability, replacing outdated components
and reducing support costs where possible. Information remained as important as
ever, but digital technologies had opened up many more possibilities.
Because it had been designed for submarine and coastal
surveillance applications, the P-3 had always been replete with data-gathering
reconnaissance equipment. However, the problem was distributing that
information to terminals on the ground or at sea. Obsolete technologies had
always hampered that task.
With obvious room for improvement in the area and a wide
array of technologies at their disposal, the P-3 community began to think about
a new way to share critical information: digital data links.
To incorporate this new technology into the existing P-3
fleet, the Navy went to L-3 Communications, provider of communications,
telemetry and avionics systems to U.S. military and intelligence agencies, as
well as to commercial telecommunications companies.
In 1998, L-3's prototype data link was installed on a single
P-3 and the command ship USS Coronado as part of Fleet Battle Experiment
(FBE)-Charlie.
Though the capability of the data link was limited to a
single video feed, the experimental P-3 was nonetheless able to communicate
information from a variety of special video cameras on the aircraft back to the
ship-based surface terminal. Based on the success of those early FBE-Charlie
tests, Navy researchers were encouraged to continue the voyage.
Later that year, the Defense Advanced Research Projects
Agency (DARPA) funded the development of a low-cost, commercial
off-the-shelf-based, open-architecture common digital data link (CDL).
Thus began the evolution of
TCDL.
The TCDL airborne system is specifically designed for
unmanned aerial vehicles (UAVs) in manned, nonfighter environments. The data
rates, modulation techniques and transmission frequencies are fully
interoperable with CDL systems.
Seeing the possibilities of this system, the Navy again
approached L-3 Communications and convinced it to expand TCDL use beyond the
P-3 platform to the S-3B Surveillance System Upgrade (SSU) aircraft.
Christened RTSDL (Real-Time Sensor Data Link), this expanded
data link system added features to the TCDL baseline, including a second video
channel, bi-directional Ethernet file transfer, two-way voice communications,
improved electromagnetic interference protection and increased range.
It is a full-duplex Ku (subfrequency) band link with a
200-Kbps command link and a 10.71-Mbps return link. RTSDL utilizes the
10.16-Mbps downlink channel (Guardrail frame format) and local area networks
onboard the aircraft and in the ground-based systems.
In April 1999, before L-3 Communications delivered the
CDL-compatible RTSDL system, the company conducted a qualifying flight on the
Predator unmanned aerial vehicle (UAV). This CDL system was capable of
transmitting one encrypted video signal at a rate of 10.71 Mbps, a marked
improvement over the first generation.
Video feed to multiple locations
FBE-Echo in 1999 became the flight test for the RTSDL. The
same P-3 used in FBE-Charlie was outfitted with RTSDL.
A modified version of the shipboard system terminal used in
FBE-Charlie was again installed on the USS Coronado. This time, however, the
RTSDL video feed was connected to the ship's closed-circuit television network,
making it possible for any person onboard to see what was being transmitted
from the air above.
A standard TCDL surface terminal was also set up at a third
location - at the littoral surveillance system/tactical exploitation system
compound on the Camp Pendleton Marine Corps Base, CA.
The data link proved capable of sending video from the plane
simultaneously to two different locations.
With the additional voice capability over the data link,
commanders on the ship and land communicated directly to the camera operators
in the air to request "eyes-on-target" information for specific images.
The file transfer capability of this system was bi-directional,
allowing digital files to be transferred from air to ground or from ground to
air. Most important, FBE-Charlie showed that it was possible to send two
different video sources (e.g., color camera video, forward-looking infrared
video, radar video) to ship- and land-based systems simultaneously in
near-real-time.
Once more, the digital data link had delivered the promised
results; the few problems with logistical support and training were not unusual
for such prototype trials.
Consequently, a report delivered at a Pentagon debriefing on
April 27, 1999, stated, "The RTSDL has demonstrated a quantum leap in P-3
connectivity with afloat and ashore commanders."
By January 2000, the S-3B SSU aircraft had been configured
with RTSDL, providing enhanced connectivity with the carrier USS Abraham
Lincoln and other large-deck ships for Commander, Cruiser Destroyer Group
Three's COMPTU-EX exercise.
Like all carriers, the USS Abraham Lincoln is equipped with
the CDL-compatible common high-bandwidth data link-surface terminal (CHBDL-ST).
CHBDL served as the surface terminal for RTSDL on the Lincoln, with the
terminal's companion Video Interface Unit distributing video from the aircraft
to television sets throughout the ship.
This test was no less successful than its predecessors. The
S-3B SSU aircraft successfully downlinked live video, voice and image files to
the Lincoln. Before the aircraft's 2000 deployment on the Lincoln, a summary
brief of its testing stated, "S-3B SSU has demonstrated network-centric,
real-time connectivity with afloat and ashore commanders via RTSDL/CHBDL."
Like the P-3 and Coronado before it, the S-3B SSU and
Lincoln were able to dramatically outpace past benchmarks for effective
communication. The SSU deployment on the Lincoln was so successful that, at the
conclusion of the six-month cruise, the SSU was rapidly redeployed to the USS
Enterprise for another six-month deployment, ending in November 2001.
Based on the success of the P-3 and S-3B exploitation of
RTSDL data, the PMA290 AIP P-3 Program Office purchased additional RTSDL
systems.
The Navy then contracted with L-3 Communications in June
2000 to make improvements to its RTSDL system, and this new generation was
designated the Tactical Common Data Link-Navy (TCDL-N). This system added a
rugged conduction-cooled chassis, a 16-channel acoustic interface, a full
TCP/IP-Ethernet interface, an increased data rate of 45 Mbps, and came at a
reduced size, weight and power consumption - as well as offering improved
operating range with same-size surface antennas.
This new system was delivered to the Navy in June 2002 and
was to be installed on a P-3 and undergo flight tests in August of the same
year.
The system's programmable modem offers several waveforms and
data rates that can be selected during flight. Replacing the radio frequency
converter and antenna can easily change the Ku band operating frequency. The
antenna itself can be changed from omni-directional to directional for
broadcast or directed transmissions. Options include bulk encryption and
programmable uplink or downlink data rates.
The TCDL ground data terminal accommodates a variety of
tactical field situations, enabling two people to set it up in a half-hour. The
design includes a 400-meter fiber-optic cable between the radiating
antenna/modem assemblies and the Link Interface Unit. An omni-directional
antenna is also provided for close-in operations. The nominal uplink data rate
of 200 Kbps includes direct-sequence, spread-spectrum modulation.
An integral part of network-centric
warfare
Though the P-3 has historically been used as an
antisubmarine craft, in recent years it has seen duty in other fields. The U.S.
Customs Service, for example, uses the plane to assist in intercepting
narcotics smuggling. Most important, the P-3 has become an integral part of
Operation Enduring Freedom, something that the TCDL system helped make
possible.
Adding the TCDL data link capability to Navy assets has
provided ship-based and land-based commanders eyes-on-target information at
distances and speeds previously unheard of - enabling air, surface and ground
forces to significantly shorten the time needed to accurately put ordnance on
target. Current TCDL systems have also been connected to the Secret Internet
Protocol Router Network (SIPRNET) for secure network transfer of digital
information. In short, the P-3 has been updated for the Internet age.
The demand for P-3 aircraft equipped with the TCDL and other
AIP systems will continue to rise. During the ongoing fiscal year 2003 budget
reviews by both the House and Senate Armed Services Committees, the P-3
community has received the funding necessary to further improve its ability to
support the United States in future military conflicts. As a result, and thanks
to the successful implementation of TCDL, P-3 Orion's star isn't likely to set
on military service anytime soon.