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Military takes a giant leap with commercial space technology
(International Defense Review; 04/01/99)
The recent decision by the US Administration to deny Hughes Space and
Communications an export license to provide the People's Republic of China
(PRC) with two Asia-Pacific Mobile Telecommunications (APMT) communications
satellites (comsats) - worth US$540 million - has focused attention on the
capability and easy availability of commercial technology.
Governments worldwide are having to face the fact that they no longer
dominate the market for space-based assets. In 1997, for the first time, the
number of US commercial launches outnumbered those conducted by the Department
of Defense (DoD), the National Reconnaissance Office (NRO), and NASA. The US
Department of Commerce estimates that the value of the country's commercial
space business will reach US$117 billion annually by 2001, compared with US$88
billion in 1997. Lockheed Martin predicts that the global business in comsats
alone will be worth US$140 billion annually by 2010.
In the case of the APMT deal, the US has expressed concern that the People's
Liberation Army would be the major user. The satellites were intended to carry
12m-diameter antennas, allowing them to handle 16,000 voice circuits
simultaneously. The PRC's interest in the low-Earth-orbit (LEO) comsat
constellation being developed by Teledesic had already begun to ring alarm
bells in the US. Adm Bill Owens, vice-chairman of Teledesic and a former vice-
chairman of the Joint Chiefs of Staff, told a conference last December that the
Chinese were "all over Teledesic". He added that "they know all abou what
technology is important for the future". These concerns have led the US
Congress to place commercial satellite technology on the munitions list from
mid-March, requiring approval for the export of any equipment valued at more
than US$15 million.
This change in the balance of power can be a blessing in disguise, however.
By using commercial approaches, the DoD implemented the Global Broadcast
Service (GBS) in 44 months from the start of the program to initial operational
capability - far faster than would traditionally have been the case for a
military system. Industry helped refine the requirements for GBS, exploiting
its knowledge of what is technologically possible and fiscally sensible. The
system is based on widely used commercial rather than rigid military
specifications, and "piggybacking" on to other launches saved further money.
The exploding demand for bandwidth affects military and commercial
organizations, as exemplified by the exponentially increasing use of the
Internet by both communities. New satcom networks operating in Ka-band, such as
Teledesic, will help carry the torrent of high-speed data.
Lockheed Martin is building four Ka-band satellites based on the A2100 bus
with 14kW of on-board power for Astrolink International, which will operate
them to provide "switched broadband in space" facilities. Both Teledesic and
Astrolink are due to enter service in 2002. Service providers are putting
forward proposals for constellations of LEO satellites operating in Ku-band,
which until recently have been the preserve of geostationary platforms.
Motorola's US$5.5 billion Iridium constellation of 66 LEO satellites which
entered service in November 1998, provides channels carrying 2.4kbit/s of
voice, data and paging traffic for handheld telephones. The next generation of
Iridium could have a capacity of up to 256kbit/s per channel. Globalstar is in
the process of populating its planned 48-satellite constellation, and the first
of 10 operational satellites to be placed in medium Earth orbit (10,400km) by
ICO Global Communications is due for launching in June. Orbcomm, already being
exploited for defense applications, will reach its full complement of 36
MicroStar LEO satellites this year.
The introduction of GBS has already provided military users with a
substantial increase in bandwidth. Hughes Space and Communications Company has
adapted the technology used in its direct-broadcast television satellites to
provide the GBS package. GBS uses transponders on three US Navy (USN) UHF
Follow-On satellites. Each carries four 130W transponders able to handle
24Mbit/s apiece. The high bandwidth available allows GBS to broadcast imagery,
video, data, and other products to ground, sea-based and airborne terminals. It
can deliver maps, intelligence data, weather reports, air-tasking orders, and
other high-volume information to field commanders in seconds - rather than the
hours or minutes taken now - for subsequent processing and display on standard
desktop computers.
In a parallel move, Hughes Global Services (HGS) has worked with PanAmSat to
adapt its SPOTcast commercial service for DoD and other government
applications. PanAmSat operates 19 satellites, and will launch a further six by
mid-2000. HGS plans to make SPOTcast for Government available from the second
quarter of this year. It will deliver high-bandwidth information, such as
digital imagery, medical data, and high-resolution live video, without the
expense of a dedicated network. Receiver equipment comprises a 2m-diameter C-
or Ku-band antenna, a PC running Windows 95/Windows NT, and a digital video
broadcast facility that may be implemented as a stand-alone
receiver/demodulator or as a PC card.
Many ground-based military programs are now adopting tri-band terrestrial
terminals that can operate in either the military X-band or commercial C- and
Ku-bands, and which exploit commercial off-the-shelf (COTS) technology to
reduce weight and cost. The AN/TSC-152 Lightweight Multiband Satellite
Terminal, that Harris is delivering to the US Air Force (USAF) as part of its
Theater Deployable Communications package, costs less than US$1 million. It
requires only two operators, compared with five for its predecessor, and takes
less than half of the airlift capacity. The USAF's Reduced Footprint Initial
Communications package, designed for rapid deployment to a theater of
operations in support up to 100 users, takes this process one step further. It
comes in seven transit cases, weighing less than 300kg in all and occupying a
volume of less than 1.7m{3}. Two technicians can assemble the system on site
and be on the air within 2h. The package costs US$270,000, plus US$135,000 for
the associated tri-band terminal with a 1.8m-diameter antenna and 100W
transceiver.
Austin Info Systems, under a joint US Army/Navy Small Business Innovation
Research contract, has developed a terminal that can operate simultaneously in
all three bands without requiring any mechanical changes. The broad-
beam/broadband, coaxial, circular waveguide feed has independent antenna
cavities for each band. The feed operates in conjunction with a 2.4m-diameter,
dual-offset, Gregorian antenna, with all electronics fitting into two transit
cases for easy deployment. The tri-band system underwent a successful
demonstration in April last year.
The US Army's Space and Missile Defense Battle Lab (SMDBL) is conducting
demonstrations and experiments, with equipment using commercial technology
under its Army Space Exploitation Demonstration Program. Several of these
support its attempts to warn troops that might be affected by theater ballistic
missile launches, the release of chemical-warfare agents, or battlefield
obstacles such as minefields. The Tactical Automated Situation Receiver
combines three COTS systems into one package: a wireless radio modem for two-
way messaging; a handheld personal digital assistant (PDA); and a Global
Positioning System (GPS) receiver. Alerts broadcast via satellite are received
at handheld data terminals integrated into a soldier's load-bearing vest,
running Joint Expeditionary Digital Information (JEDI) software. This supports
two-way messaging, tracking of friendly forces, and situation awareness of
known enemy movements.
Booz Allen & Hamilton has developed a family of JEDI-compatible PalmCOP
software for handheld PCs/PDAs and communications gateways. These permit an
over-the-horizon extension of the Global Command and Control System, via
satellite networks such as Iridium. The software can run on a variety of
handheld platforms, including the Windows CE-based Philips Nino 320, Casio P-
2400 and HP 620 LX; the DATUS PNA with an internal GPS receiver; and the Apple
Newton MP 2100.
These can interface with small radios from suppliers including Racal,
Ericsson, Orbcomm and ICOM, and with military sensors such as the Rockwell
Collins PLGR GPS receiver and Viper laser ranging binoculars.
Smart switch
Another SMDBL initiative, Tactical Vehicle Smart Communications Switch
(TAVSCOMS), explores the ability of a smart switch to automatically detect and
select whichever communications medium - line-of-sight radio or commercial
satcoms - is most suitable for the reliable exchange of data at any given time.
Navies are also exploiting commercial comsat technology. In July 1998, the
USN's Space and Naval Warfare Systems Command (SPAWAR) selected Raytheon
Systems Company to provide an initial 14 shipboard antenna systems for use with
GBS, with options on a further 300. The Ku/Ka-band antennas are COTS
derivatives of the AN/USC-38 EHF and AN/WSC-6 SHF shipboard terminals that
Raytheon already supplies to the USN. The AN/WSC-8(V) shipboard terminal that
Harris is supplying to the USN is based on those that the company provided for
the earlier Challenge Athena III demonstration, which largely convinced the
service of the benefits to be gained from a COTS approach. The WSC-8(V)
operates via commercial C-band satellites, providing links at data rates up to
1.544Mbit/s. It can handle a wide range of traffic, from satellite imagery to
personal communications.
Efficient bandwidth management can help users make the most of limited
satcom capacity. The Challenge Athena III system for example, allocates fixed
bandwidth segments to specific functions such as the Joint Service Image
Processing System, and tele-medicine. These tie up 100% of the assigned
bandwidth, regardless of the actual traffic. The USN and US Marine Corps (USMC)
are conducting a proof-of-concept demonstration of the Bandwidth Efficient
Satellite Transport Network (BESTNET), using a commercial bandwidth-management
system developed by Innovative Communications Technology that should help
alleviate this problem. The network is installed aboard the USS Ponce (LPD 15)
and Gunston Hall (LSD 44), part of the Kearsage Amphibious Ready Group (ARG),
scheduled for deployment this month (April). BESTNET uses a point-to-multi-
point architecture that provides high bandwidth by means of a broadcast forward
and simplex return procedure. The demonstration is intended to identify the
mission and cost benefits of using such a COTS approach.
The USMC requires a high bandwidth to support split ARG operations in the
Atlantic. In parallel, the Navy Exchange Service Command (NEXCOM) needs
periodic access to additional bandwidth for 'quality-of-life' (QOL) services
such as personal telephone calls by the embarked personnel. SPAWAR Systems
Center is also participating as part of its IT21 initiative. USMC staffs
embarked on amphibious ships have routinely required more communications
capacity than can be provided by the USN, using Inmarsat-A and -B terminals
with 1m antennas. This shortfall has traditionally been remedied by installing
standard Inmarsat systems of 64kbit/s capacity - more recently augmented by
256kbit/s four-channel terminals - as a temporary measure during split-ARG
operations.
For its part, NEXCOM has installed its own C-band terminals aboard LPDs and
LSDs, to meet increased QOL demands while reducing costs (US$1/min for ship-to-
shore calling via AT&T, compared with approximately US$6/min using earlier
Inmarsat terminals). The USMC has taken advantage of the resulting excess
capacity by installing local-area networks and baseband equipment aboard the
ships, and by incorporating statistical multiplexers for dynamic management of
bandwidth. The success of this venture persuaded the participants to
investigate a completely merged architecture using BESTNET, which could form
the basis of future IT21 systems.
Maritime C-band terminals continue to shrink, making them suitable for
installation aboard smaller vessels. Commercial Satellite Systems, in
collaboration with Comsat Laboratories, recently introduced its CS2000 terminal
with a 1m antenna (compared with the standard 2.4m).
The use of direct-sequence spread-spectrum operation with a code-division
multiple-access waveform, eliminates off-axis emissions and permits
communication at up to 64kbit/s.
Proving reliable data communications via satellite from a ship underway in
heavy weather has traditionally required antennas designed specifically to meet
military specifications. SeaTel's Series 96 and 97 stabilized antennas -
ranging from 1m to 2.4m in diameter - are COTS equipment, but meet the relevant
military standards for shock, electromagnetic interference, and radio-
frequency interference, and exceed that for vibration. They employ a patented
three-axis stabilization system that allows the antenna to respond to ship
motion as fast as 90/s. A conical-scanning system samples the signal strength
in each quadrant of the antenna 400 times a second and feeds the information
to the system's TAC 92 computer. This micro-steps the antenna using high-
torque motors to equalize the signal. This results in a maximum pointing error
of 0.2, even in the presence of ship motion through 25 in roll and 15 in
pitch, at frequencies up to Ka-band.
The use of Ka-band will allow naval users to take advantage of much higher
data rates for ship-to-shore communications via satellite. In October 1998, a
team from the US Naval Research Laboratory, NASA's Lewis Research Center, and
industry, demonstrated two-way Ka-band transmission at 45Mbit/s from a vessel
underway, via NASA's Advanced Communications Technology Satellite (ACTS). This
compared with a previous maximum of 2Mbit/s for transmission from a mobile
platform. The Shipboard ACTS Ka-band Experiment used SeaTel's 1m-diameter
antenna with a tracking pedestal. An operational implementation of this
technology would allow small combatants to receive the volume of data now only
available to large platforms.
Although the US has the highest profile in the use of commercial comsats for
defense applications - not least because changing the military mindset is no
spectator sport for the squeamish - other countries and alliances with large
areas of responsibility are following suit. NATO is debating whether to buy its
next generation of comsats, or lease capacity on either commercial or national
military systems. The UK is conducting a similar analysis. The Australian
Defence Force (ADF) is introducing a variety of new satcom facilities under its
multi-phased Joint Project 2008. The Defence Mobile Communications Network
(DMCN), established under Phase 2, uses services provided by the Optus
Mobilesat commercial network. Under Phase 3D, the ADF will fly a military
payload - operating in the UHF, Ku-, X- and Ka-bands - aboard the Optus C1
joint military/commercial satellite to be launched in 2001. The ADF also plans
to replace the DMCN with mobile telephones - operating via a LEO satellite
constellation - in about 2004, and to conduct a technology demonstration of a
broadband system similar to GBS.
Military uses of commercially supplied imagery are also increasing
dramatically. Presidential Decision Directive 23, issued in 1994, freed US
companies to begin acquiring and marketing high-resolution satellite imagery
that had previously been the preserve of government organizations. Market
research conducted by Merrill Lynch projects that revenues in this field will
grow from US$350 million in 1997 to US$6.5 billion a decade later. The US
National Imagery and Mapping Agency (NIMA) plans to spend up to US$100 million
over the next five years on buying such imagery from Earthwatch, Orbimage and
Space Imaging. The NIMA will 'drape' the imagery over precisely matched digital
elevation data of the same area to generate three-dimensional databases for
applications such as mission planning and rehearsal. Space Imaging's two Ikonos
satellites will provide monochrome and color images with a resolution of 1m,
and multispectral images with a resolution of 4m.
The US Army's SMDBL's Civil/ Commercial Imagery Systems program comprises a
series of related projects. These include: Warfighter I - using a USAF Research
Laboratory hyperspectral imagery (HSI) package installed aboard the Orbview-4
commercial electro-optical/multispectral observation satellite - which is
planned for launching in 2001; testing of HSI collection from airborne
platforms; and Eagle Vision II, funded by the NRO. Eagle Vision II, an enhanced
version of the original Eagle Vision acquired under a Foreign Comparative Test
program, will accept inputs from platforms such as SPOT, Landsat, Radarsat and
Quickbird. It can then process them and supply the results in near-real time
as unclassified panchromatic, multispectral, and radar images for use by
existing mission planning, topographic, and intelligence systems.
ERIM International is upgrading the existing Eagle Vision under a contract
from the USAF's Electronic Systems Center. The enhancement - Joint Eagle -
merges two systems developed by ERIM: the Eagle Vision Data Integration
Segment, which processes commercial satellite imagery; and the National Eagle
System, which merges national and commercial imagery into a common software
baseline at two additional operator positions. Joint Eagle produces merged
multispectral and orthorectified mosaic data products compatible with the Joint
Analysis Center at Molesworth in the UK, and with mission planning and
rehearsal systems such as the USAF's AFMSS, the US Navy's TAMPS, PowerScene,
and TopScene.
The US Office of Naval Research, in partnership with the Naval Research
Laboratory, has awarded Space Technology Development Corp (STDC) a contract to
build the Navy Earth Map Observer (NEMO) remote-sensing satellite for launch
next year. NEMO, based on the Space Systems/**Loral** Globalstar bus, will
combine commercial technologies with USN developments in HSI. The sensor's
area coverage and sensitivity will allow it to gather synoptic imagery over
thousands of square kilometers of land and sea. The satellite will map most of
the Earth's surface - including much of the littoral region - and make multiple
passes over selected regions, to permit the validation of information-
extraction algorithms under a full range of geographic and environmental
conditions. NEMO will be the first commercial production spacecraft to be used
by the DoD. STDC will work with its business partners - Space
Systems/**Loral**, AlliedSignal Technical Services, and Applied Coherent
Technology - to market HSI and panchromatic data to commercial users.
Landsat launch
The performance of civilian Earth-observation satellites is also steadily
increasing. NASA's Landsat-7, due for launching this month, carries a Raytheon
Enhanced Thematic Mapper Plus sensor that provides a resolution of 15m for
panchromatic imaging - twice as fine as its predecessor. SPOT 5, funded jointly
by the French space agency and Matra Marconi Space, will carry a High-
Resolution Stereoscopic (HRS) payload when it is launched in 2002. HRS will
provide a ground resolution of 5m - compared with 10m for the previous
generation of SPOT satellites - and supply stereo imagery to assist in
construction of digital terrain models.
Military users are also increasingly taking advantage of imagery from space-
based synthetic-aperture radars (SARs). The Shuttle Radar and Topography
Mission (SRTM), due for launch later this year, is a joint project by
commercial (NASA) and military (NIMA) agencies to map 80% of the Earth's land
surface - between 60N and 56S - in three dimensions.
The SRTM will use enhanced versions of the Spaceborne Imaging Radar (SIR-C)
and X-band Synthetic Aperture Radar (X-SAR) that flew two successful missions
aboard a Shuttle in 1994. During the forthcoming 11-day flight, the SRTM will
collect data on points spaced every 30m or so on the surface, with absolute
accuracies of 20m and 16m respectively in the horizontal and vertical planes.
Canadian sister companies Satlantic and IOSAT have developed Sentry, a
transportable ground station consisting of a 5.4m-diameter antenna and a
shelter housing COTS-based equipment. The latter includes a High-Rate SAR
Processor, developed specifically for this application, that can provide SAR
imagery within five minutes of its receipt. The shelter also accommodates one
or more workstations running Satlantic's Ocean Monitoring Workstation (OMW)
software, which can supply tactically useful information - such as ship
locations, and wind and wave fields - in 3-5min. The software is divided into
modules that operate independently on different parameters of the imagery, with
their outputs then being collated to produce maps or customer-specified files.
OMW has demonstrated a ship-detection rate of up to 97% when operating with
Radarsat.
Sentry participated in the combined Canadian/NATO exercise MARCOT/ Unified
Spirit 98 in June last year, during which it was tasked with providing ship
locations within an hour of receiving SAR imagery (compared with several days,
or even weeks, using earlier systems). The system downloaded a total of 30
Radarsat images during the exercise, achieving a best time of 26min and an
average of 54min from the satellite being overhead to delivery of products to
the customer (including processing by the OMW).
In November 1998, spurred by North Korea's test-firing three months earlier
of a ballistic missile that crossed Japanese territory, the country's cabinet
approved a plan to deploy four observation satellites. Mitsubishi Electric will
build the satellites for launching from 2002, under a program costing around
US$1.5 billion. Two will carry SARs with 1-3m resolution, with the other pair
using optical sensors providing 1m resolution.
(Copyright 1999) |
