New Verifications Technology and Issues: Space and Airborne Monitoring

Prepared for presentation at the technical workshop on Safeguards Verification Technologies and Related Experiences, IAEA, Vienna, May 12-15 1997. This paper is the sole responsibility of the author, and does not necessarily reflect the views of the Israeli government. All material used in this study is based on open sources.

The period after World War I was marked by a number of arms limitation agreements, including the Geneva Protocol prohibiting the use of chemical weapons, the Washington and London naval arms limitation treaties, and the restrictions on German rearmament in the Versailles Treaty. These were generally marked by very limited verification and compliance mechanisms.

In contrast, and as a result of this experience, the framework for arms control and disarmament that developed following World War II placed a major emphasis on verification. "Trust and Verify" became the motto of the US Arms Control and Disarmament Agency. During the period of the Cold War, with the policies of mutual deterrence and the constant threat of conflict, the level of trust was very low, and the emphasis on verification was strong. Under such conditions, and in the midst of an intense conflict and arms race, governments naturally consider the possibility that a government or regime would exploit weaknesses in the limitation agreement and verification system to conceal an illicit weapons program. As a result, in this framework, verification systems based on third parties and international organizations were and are viewed as insufficiently exacting to deter violations that would threaten national security and survival.

During the Cold War, and even after the collapse of the Soviet Union, in US-Soviet arms limitation agreements, the verification systems were very detailed, and were based on unilateral or mutual arrangements. As long as significant military capabilities continue to exist, and political and economic cooperation (the basis for some form on trust in the international and regional context) is relatively limited, such detailed and mutually enforced safeguards and inspection systems remain fundamental to the arms control process.

The first agreements, such as the 1963 LTBT and the 1972 SALT and ABM Treaties, were based on "national technical means of verification", primarily seismic networks and overhead reconnaissance satellites. This limited transparency served the common interests of both sides in preserving stability and preventing conflict. As political and security conditions changed, particularly in the mid-1980s following the major changes produced by the advent of glasnost and perestroika in the Soviet Union, the scope of transparency increased. The growth of extensive political and economic cooperation allowed for more extensive arms limitation agreements and accompanying verification measures. During this period, verification provisions for the INF, CSCE and CFE Treaties included on-site inspections, and provisions for aerial overflights. In 1992, the Treaty on Open Skies was signed. It is designed to provide a mechanism for verifying and monitoring these and related agreements, both formal and informal. [ Jeffrey D. McCausland, Conventional Arms Control and European Security , Adelphi Paper No.301, (IISS: London, 1996), p.18.]

In this analysis, we will examine the technology and application of satellite and airborne verification systems in the framework of arms control agreements. As will be seen, the combination of these platforms and appropriate sensors can provide a degree of transparency for verifying agreed treaties that contribute to the security of all the parties involved. However, as will also be noted, these systems are based on "dual-use technology", which could also be used for non-peaceful purposes. In the absence of the appropriate political and security-related conditions, and given the very high degree of transparency provided by such overhead platforms, the potential for wide distribution of images (in contrast to the very narrow and stabilizing role for NTM) could be destabilizing and even contribute to conflict.

I. Space and Airborne Monitoring in the Verification Spectrum

The technologies and techniques that are available for monitoring and verification cover a wide spectrum. These include 1:) Site visits and on-site inspections (permanent, periodic, and challenge), 2:) Passive remote systems, such as seals (mechanical and electronic) and cameras that are checked periodically, 3:) Active remote systems, that transmit images or status reports as required, particularly for materials in transport, 4:) Sampling techniques, and 5:) Overhead data collection and imaging.

Overhead imaging can be conducted by a variety of systems, including balloons, aircraft, (piloted and unmanned) and satellites. The first successful reconnaissance satellite (Corona 13) was launched by the US in August 1960, and since then overhead imaging and data collection has been used increasingly to provide a basis for monitoring and verifying compliance with international, regional, and bilateral limitation agreements and arrangements. [ On the link between strategic intelligence and arms control, see Catherine McArdle Kelleher and Joseph E. Naftzinger, editors , Intelligence in the Arms Control Process: Lessons from the "INF ", Center for International Security Studies at Maryland, U. Of Maryland, 1990] The first such applications began in 1963, following ratification of the Limited Test Ban Treaty, which specified that the provisions would be monitored via national technical means (NTM) of verification. The US used space-based sensors for this purpose. In 1972, the US-Soviet agreements on strategic arms limitations (SALT I) and the deployment or testing of anti-ballistic missiles (ABM Treaty) also included provisions for verification based on NTM. The texts of these treaties specifically prohibited interference with the activities of NTMs in this context. [ Article XII of the 1972 ABM Treaty, and Article V of the SALT I agreement, signed in Moscow in May, 1972, state: "1.For the purpose of providing assurance of compliance with the provisions of this treaty, each Party shall use national technical means of verification at its disposal in a manner consistent with generally recog nized principles of international law. 2.Each Party undertakes not to interfere with the national technical means of verification of the other Party operating in accordance with paragraph 1 of this article. 3.Each Party undertakes not to use deliberate conceal ment measures which impede verification by national technical means of compliance with the provisions of this treaty." ] In addition, the images and data obtained by these systems was highly classified, in recognition of the potential destabilizing impact of the distribution of such information.

II. Space Monitoring Technology

Satellite verification and monitoring technologies can be divided into three categories, based on the nature of the sensors involved: optical imaging (visible and infra red), radar imaging, and radio. Each has particular properties, as well as relative advantages and disadvantages depending on the nature of the verification requirements.

a) Optical imaging technologies include film and charged coupled devices in the visible (0.4 to 0.8 micrometers), near-infra-red light portion of the spectrum (0.8 to 1.1 micrometers) and infrared portion. ("False colors" are used to enhance particular items in these images). Initially, exposed film was returned in recoverable re-entry vehicles, and later developed on board and scanned digitally, then transmitted to ground. [ Albert D. Wheelon, "Corona: The First Reconnaissance Satellites", Physics Today , February 1997.] More advanced systems use CCDs which transmit data directly to ground stations. [ Stephen E. Doyle, Civil Space Systems: Implications for International Security , (UNIDIR, Geneva: 1994). ] The first US Corona satellites had a resolution of 8 meters, and within a short time, this had been reduced to 2 meters. [ Albert D. Wheelon, "Corona: The First Reconnaissance Satellites", Physics Today , February 1997, p. 29. ] The most sophisticated military reconnaissance satellites are reported to have resolutions of 10 to 5 centimeters, and if equipped with flexible optics to correct for atmospheric distortions, may be able to achieve resolutions of 1 to 3 cm. [ A.S. Krass, "Arms control Verification", in Arms and Disarmament: Sipri Findings , edited by Marek Thee, (Oxford University Press: New York, 1986), pp.304, 371 - 378.]

As noted, the US also operates high-altitude satellites designed to detect nuclear explosions in space, on the ground and in the air. This system was initially known as VELA Hotel, and it was designed in the early 1960s to monitor compliance with the Nuclear Test Ban Treaty then being negotiated in Geneva. The first pair were launched in 1963, a few days after the LTBT went into effect. [ "SMC Remembers The Vela Program", Astro News, 7 February, 1997, Space and Missile Systems Center, Harry Waldron History Office, Los Angeles. (http://www.laafb.af.mil/SMC/PA/Astro_News/97/Feb/07/vela.htm)] More recent systems include optical flash detectors (bhangmeters), X-ray emissions, and a electromagnetic pulse sensors, and are located on Defense Support Program (DSP) satellites, and Global Positioning System (GPS) satellites. [ DOE Marks 60th Launch of Satellite-Borne Nuclear Monitoring Technology , Press Release, (US Department of Energy: Washington, DC, 17 July, 1996); see also Bhupendra Jasani, Verification of a Comprehensive Test Ban Treaty from Space: A Preliminary Study,UNIDIR research paper 32, (UNIDIR: New York, 1994)] (The DSP satellites also include infrared sensors to detect the heat emitted by ballistic missile launches, and could be used to monitor adherence to agreed limitations on such launches. Low orbit infrared detectors are also employed, and the US in planning to deploy a Space-Based Infrared System (SBIRS), with up to 24 low and high-altitude satellites to replace the DSP.) [ National Missile Defense, Risk and Funding Implications for the Space-Based Infrared Low Component , (USGAO: Washington DC, 1997).] During the 1970s and 1980s, the Soviet Union also launched early warning satellite systems. [ TRW Space Log, 1957-1987 , Summary Log of Space Launches, 1957-1987, (TRW Space and Electronics Group: Redondo Beach, California, 1988)] (See Table 1.) These space systems provide important elements of international stability, demonstrating the legitimacy of national and defensive applications of space assets for verification, early warning, and communication.

b) Radar Systems are divided into fixed-array and phased-array, and include synthetic aperture, inverse synthetic aperture, and infra-red technology. SAR is a side-looking radar with a short antenna, which can behave like a long antenna with a narrow beam. Signals from the short antenna are added electronically and synthesized to give the effect of a long one. [ Stephen E. Doyle, Civil Space Systems: Implications for International Security, (UNIDIR: New York, 1994).] The advantages of SAR include imaging capabilities both at night and through cloud cover. Radio imaging techniques permit data to be collected at wavelengths beyond the limits of photographic film, including the infrared and ultraviolet regions that are beyond the capability of the human eye. However, SAR systems are generally unable to match the high resolutions of the best optical sensors, but still are capable of 1 to 3 meter resolution. [ Krass, p. 303.] Radar imagers such as the US Lacrosse satellites can be used to make contour maps of terrain, and when combined with visual imagery taken on other sensing systems, allows for the construction on 3-dimensional imagery of surface characteristics to show ground objects at different angles.

c) Verification using Space Based Sensors for radio signals

In some cases, the monitoring and verification of treaty limited items can be accomplished through the use of space-based radio signal receivers. Among the items and limitations that can be verified in this way are satellite and rocket launches and flight paths (by monitoring telemetry, telecommand, and tracking technology). The US maintains radio monitoring satellites in geosynchronous orbits (Rhyolite, Chalet, and Aquacade). Together, they are able to intercept signals from any point on the earth’s surface. [ Krass, P. 303.]

Characteristics of Sensors

For all three sensor technologies, the main factors in determining the capability for verification and monitoring are resolution, frequency of observation, and angle. Although optical imagers are placed in the low orbits in order to have the highest possible resolution, such orbits are still at altitudes on the order of a few hundred kilometers. The challenge of space-based monitoring is increased by the need to maintain a stable sensing plane stable while traveling at orbital speed. [ Stephen E. Doyle, Civil Space Systems: Implications for International Security , (UNIDIR: Geneva, 1994).] A satellite’s capabilities are determined by parameters such as image-collecting sensor characteristics and the verification cycle. In designing the system, technical elements include the orbit (altitude, angle of inclination, and orbit period), weight, and service life, launch vehicle capability, data transmission system, and overall system-control technology . [ Gerald Steinberg, "Satellite Capabilities of Emerging Space Competent States", in Alves, ed., Evolving Trends in the Dual Use of Satellites , (UNIDIR: Geneva, 1996), p.23.]

The resolution of the system determines the degree of detail in the image or data, and the reliability of the monitoring or verification system with respect to the agreed limitations to be monitored. The term GSD (ground sample distance) is used to classify resolution, with specific GSDs required for verifying individual items. GSD is defined as the length and width of each pixel in a digital image (or the film equivalent) projected onto the ground. [ Gupta and Pabian, "Investigating the Alegations of Indian Nuclear Test Preparations in the Rajasthan Desert", Science and Global Security, vol 6, 1996, p.116.] This process can be subdivided into four stages: detection, recognition, identification, and description. [ Access to Outer Space Technologies: Implications for International Security , Research Paper No.15, (UNIDIR: New York, 1992), p.68.] Each requires a different resolution capability (GSD). For example, a GSD of 4.5 m is necessary to detect an aircraft on the ground while 0.9 m GSD is necessary to identify this aircraft. [ Access to Outer Space Technologies: Implications for Internationa l Security, Research Paper No.15, (UNIDIR: New York, 1992), p.68. The smallest bits in an image are called pixels, and are transmitted in binary form. For scanning devices, the term "instantaneos field of view (IFOV)" is used, and defines the size of the area in the image viewed by the sensor. See Bhupendra Jasani, Verification of a Comprehensive Test Ban Treaty from Space: A Preliminary Study, UNIDIR research paper 32, (UNIDIR: New York, 1994), p.9]

For the purposes of verification and monitoring, satellite imaging capabilities can be divided into three categories, according to resolution.

-1)High resolution systems (four or five meters or less);

-2)Mid-level resolution (ten meters to four meters)

-3)Low-resolution (30 meters to ten meters) [ For weather information and other large-area features, such as smoke from bombing campaigns, or for tracking large troop movements in the desert, even lower-resolution imaging systems have some military utility. See Vipin Gupta, " METEOSAT Imagery and the Second Gulf War" in John H. Poole and Richard Guthrie, eds., Verification Report 1992: Yearbook of Arms Control and Environmental Agreements , pp. 219-229.]

These designations are somewhat arbitrary, but in general, systems with a GSD of four to five meters or less are defined as high-resolution imagers, although the area covered is also minimized. [ For a detailed analysis of the intelligence implications of different resolutions and other technical characteristics, see Vipin Gupta, "New Satellite Images for Sale: The Opportunities and Risks Ahead" International Security , Vol. 20 No 1, Summer 1995. ] Identification of the characteristics of treaty limited items, such as weapons systems and deployments of troops (order of battle), require a resolution of 1 meter or less. [ Mary Umberger, "Commercial Observation Satellite Capabilities", in Commercial Observation Satellites and International Security , Michael Krepon, Peter D. Zimmerman, Leonard S. Spector, Mary Umberger eds., (St Martins Press: New York, 1990) p.10.] Five-meter resolution images are useful to monitor limits on tank and aircraft shelters within bases, as well as other limitations. Imaging systems with 15 to 30 meter resolutions might be sufficient to monitor the absence (or demonstrating the presence) of large scale tank concentrations in limited force zones, as well as the detection of large area targets, such as space launching facilities, railroad yards, and coastal features. (The ability to detect, identify, and analyze any feature in an image also depends on the type of the analysis, including computer software and trained human-interpretation. [ Access to Outer Space Technologies: Implications for International Security , Research Paper No.15, (UNIDIR: New York, 1992), p.68.] ) Additionally, some monitoring and verification tasks do not require fine resolutions; rather, they only require detection of a battlefield environment or area where the enemy is not present. In this case, 3D stereopairs and infra-red sensors can access terrain conditions, devise strike routes and detect movement at night. [ Access to Outer Space Technologies: Implications for International Security , Research Paper No.15, (UNIDIR: New York, 1992), p.68. Other sensors designed for deforestation detection can detect mass losses of vegetation due to chemical weapons. Also see Steinberg in Alves, p.23.] Infrared detectors are used to locate and identify temperature related phenomenon on the ground. In an analysis of the role of various monitoring systems with respect to the Iraqi nuclear weapons development program, Anthony Fainberg argues that increased use satellite- based infrared sensors "to detect heat rejection more readily from facilities that may be used to produce nuclear fuel for weapons". [ Anthony Fainberg, "Strengthening IAEA Safeguards: Lessons from Iraq", Center for International Security and Arms Control, Stanford University, 1993, p.1] Such facilities include centrifuges and elector-magnetic isotope separation (EMI) for uranium enrichment and even underground nuclear reactors for producing plutonium. (Infrared sensors at 10 to 20 microns should also be able to detect changes in the temperature of rivers and lakes due to venting of coolant.) [ Fainberg, p. 21] (See Table 2.)

The frequency of observation is determined by the repeat period of the satellite orbit -- the time it takes for the ground track of a satellite to retrace a previous track exactly. In the case of SPOT, for example, the effective repeat period is 5 days at the most (on the equator), compared with 14 days for the Russian Resurs satellite. [ Vipin Gupta, "New Satellite Images for Sale: The Opportunities and Risks Ahead" International Security , Vol. 20 No 1, Summer 1995, p.3. Technically, the SPOT repeat period is 26 days, but by tilting the viewing axis of the cameras off-nadir, this is reduced substantially. Laurence Nardon, "Test Ban Verification Matters: Satellite Detection," Vertic , 1994, p. 24.] Situations requiring monitoring can evolve rapidly, and such systems must be time effective (a short amount of time between notification of possible violations and action in response). [ WEU, Airborne Surveillance , Report submitted on behalf of the Technological and Aerospace Committee, Assembly of the Western European Union, Document 1547, 13 November 1996, p.5]

The third factor is the angle of the sensor with respect to the ground track. In some applications, the need for frequent passes can be decreased significantly with imaging to the left and right of the orbital track (oblique imaging), and is used, along with fore and aft imaging, to obtain stereo pairs, which are used to detect and measure movement of the target on the ground. [ Gupta, p.108.]

III. Airborne Monitoring

Aircraft-based monitoring and verification is technologically very similar to orbital monitoring. Optical and radar sensing systems are employed in both, and factors such as resolution, frequency of observation, and angle are equally important in airborne monitoring. However, there are five import differences in verification from aircraft.

1) Altitude: Aircraft are closer to the ground than space-based platforms, and this increases the potential resolution (GSD) of sensors.

2) Payload: aircraft can be significantly heavier than satellites, carry more and better equipment.

3) Cost: the cost of a dedicated satellite verification system is generally at least $1 billion [ Krass]

4) Flexibility -- satellites move in fixed orbits, and movements are slow and limited by on-board fuel.

5) Legal Status: While satellite overflights are not limited under international law, aircraft are prohibited from entering the airspace of sovereign states with their permission. As a result, airborne verification and monitoring must either be conducted from outside the airspace of the states via high altitude flights up to and along the borders, or with their agreement and cooperation to allow direct overflights.

There are a number of different types of platforms that can be used for airborne monitoring and verification, including fixed wing aircraft, helicopters, and RPVs or Unmanned Aerial Vehicles (UAVs).

1) Fixed wing platforms can reach high altitudes, allowing for medium-size target recognition and a wide field of view. For example, the U-2 aircraft which is used to monitor compliance with the limited force provisions of the Egyptian-Israeli peace treaty and the 1974 Israel-Syria disengagement agreement, covers an area of up to 600 km at an altitude for 30 km), potentially covering an entire limited force zone using different sensors. (At 20 km, the effective observation range is between 280 km and 170 km.) Airborne equipment includes observation sensors and remote transmission systems. There are also proposals to use platforms with larger payloads, such as the US JSTARS system (used in both the Gulf War and the Bosnian conflict), and allowing for use of SAR and many other sensors, and able to provide resolution and coverage ranging from 16m2 to 250,000 km2. [ WEU, "Airborne Surveillance", pp.10-12.]

2) Helicopters (rotary wing platforms) operate at lower altitudes and are very flexible, allowing for faster responses to changes in the position or status of the objects of verification, more time on station, increased resolution, repeat passes, and changes in the target zone, in response to real time observations. They can be used in conjunction with high-altitude fixed-wing systems for observing area masked by the contours of the terrain. However, their range is relatively limited.

France has developed a helicopter-based verification system, known as Horizon. It is programmed to take radar images of any vehicle moving faster than 6 km/hr. Horizon can detect, locate, analyze and classify any moving target up to a range of 200 km, day or night, in all weather. The helicopters have multimode radar (MTI, mapping, and intercept) and can fly for up to four hours at distances of up to 1000 km at a height of up to 4000m. [ WEU, "Airborne Surveillance ", p. 14]

3) UAVs generally have operating ranges limited to a few hundred kilometers and in terms of monitoring systems, can be divided into three categories:

1. regimental level- corresponding to a range of roughly ten km (used by army regiments).

2. tactical level- corresponding to a range of approximately 100km.

3. strategic level- corresponding to a range of 1500 km (used by air forces).

The French firm Sagem is developing both the Crecerelle (short range) and the Sperwer (for the Dutch army - long range). The Crecerelle is used for tactical monitoring and target-acquisition tasks, has a maximum speed of 250km/hr, an operating range of 60-70km and can reach a height of 3500m. [ WEU, "Airborne Surveillance" , p.15]

IV. Space Monitoring Applications- verification, threat assessment, peacekeeping

The first US reconnaissance satellite programs code named "Corona", "Keyhole" (KH), "Samos" and "Discoverer" were developed in order to monitor Soviet missile deployments. [ Dino A. Brugioni, "The Art and Science of Photoreconnaissance", Scientific American , March 1996. ] These satellites took thousands of photographs from orbit, after which retrorockets triggered the reentry of the film capsule, which was recovered either in mid-air, or on the surface of the ocean. Beginning in 1962, dual cameras were used to make stereoscopic images. [ Dino A. Brugioni, "The Art and Science of Photoreconnaissance", Scientific American , March 1996. ] The 1995, declassification of Cold War satellite data made public over 800,000 images taken between 1960 and 1972. [ Caroline Smith, CIA Satellite Photos Showed Soviet Cold War Ability", Reuter, 10 November 1996.]

Following the Cuban Missile Crisis in October 1962, Washington and Moscow began to seek means of reducing the risk of accidental war, and preemptive strikes. In this context, the use of "observation satellites to promote international security" began to be discussed. US Deputy Assistant Secretary of State Richard Gardner stated that "Space photography can contribute to the reduction of risks of war ... And it is a use of space which may prove important someday in monitoring disarmament agreements." [ See Gerald M. Steinberg, Satellite Reconnaissance , (Praeger: New York, 1983).]

As a form of NTM, Corona provided images that identified Soviet nuclear assistance to the PRC, and the site of early Chinese nuclear tests [ V. Gupta and D. Rich, "Locating the Detonation Point of China's First Nuclear Explosive Test on 16 October 1964", International Journal of Remote Sensing , 1996, vol 17, no 10, p.1969-1974.] , created baseline data for SALT I, and revealed details on the Soviet ABM program and sites (Galosh, Hen House). (In the mid-1970s, the US complained that the Soviet Union was covering submarine construction sites, thereby interfering with satellite observation, and in violation of SALT 1. Similarly, the USSR filed a complaint with the Standing Consultative Commission charging that the US was covering ICBM silos with shelters while upgrading Minuteman missiles. In response, the USSR removed the covering at the submarine bases, and the US removed them entirely.) [ Gloria Duffy, Arms Control Treaty Compliance, Vol. 2, p.287.]

More recently, both the US and France have developed and operated lower-resolution civilian imaging systems, known respectively as LANDSAT and SPOT. LANDSAT, with a monochromatic resolution of 30 m, a multispectral Thematic mapper, and an infrared sensor for detecting ground temperature variations with a resolution of 120 meters, was first launched by the US in 1972, and the first 10m resolution SPOT satellite was launched by France in 1986. [ Michael Krepon, "The New Hierarchy in Space", in Michael Krepon, Peter Zimmerman, Leonard Spector, and Mary Umberger, eds . Commercial Observation Satellites and International Security (St Martin's Press: New York, 1990), p,22. Also see Peter Zimmerman, "From the SPOT Files: Evidence of Spying", Bulletin of Atomic Scientists , vol 45, no 7, July 1989, pp.24-25.] SPOT 2 was placed in orbit in 1990 and SPOT 3 in 1993. SPOT-4 is scheduled for a 1997 launch, and will have 10m panchromatic resolution like its predecessors, and an additional mid-infrared imaging capability. SPOT 5A and 5B (scheduled for launch in 2000 and 2003 respectively) will have 5m panchromatic resolution. [ Robert K Ackerman, "Remote Sensing Advances Spur Geospatial Products", Signal , June 1996.] HELIOS, France's military satellite, was launched in 1995 and has a 1m GSD. France plans to launch HELIOS 2, and the more advanced HORUS (nee OSIRIS) all weather, space intelligence system in 2005. [ AW&ST , 6 January 1997.] In addition, India, Israel, China, Canada and the ESA have the ability to develop dual-use satellite systems for Earth resources or maritime observation satellites and disarmament-verification purposes..

The lower level LANDSAT and SPOT systems have some limited verification and monitoring applications. Japanese defense analysts attempted to use LANDSAT images to identify a Soviet air base and to conclude that these improvements would allow the TU-22M Backfire bomber to be flown from this site. [ Jeffrey Richelson, "Implications for Nations Without Space - Based Intelligence - Collection Capabilities", Krepon et al.] Additionally, Norwegian academics sought to use LANDSAT images with 80 and 30m resolution to detect evidence of the Soviet naval build-up on the Kola peninsula. [ Peter Zimmerman, Remote Sensing Capabilities, Superpower Relations and Public Diplomacy , in Krepon et al, p.35.] SPOT images were used to confirm the construction of a chemical warfare plant in Rabta, Libya [ Michael Krepon, "The New Hierarchy in Space", in Michael Krepon et al, p.27. ] , and provided images of the CSS2 missiles Saudi Arabia purchased from China. [ Richelson in Krepon et al, p.55.] (See Table 3.)

The verification provisions of the Comprehensive Test Ban Treaty are based on global seismic and radionuclide monitoring and overflights, but the CTBT does not include specific reference to space-based systems. However, the CTBT also provides for the use of supplementary data provided on the basis of NTM, in evaluating applications for on-site inspections. Under these provisions, some analysts have argued that satellite data could provide information in detecting potential test sites and collaborating other data regarding suspected nuclear explosions. Nardon claims that satellite images can "add extra evidence to anomalous seismic or radioactive events suggesting that a test has occurred. In both cases, such images would show the precise zone in which an on-site inspection (OSI) could be conducted." [ Laurence Nardon, "Test Ban Verification Matters: Satellite Detection," Vertic, 1994, p.1. See also Bhupendra Jasani, Verification of a Comprehensive Test Ban Treaty from Space: A Preliminary Study, UNIDIR research paper 32, (UNIDIR: New York, 1994), p.4.] Similarly, Gupta and Pabian argue that satellite based observation can provide a useful tool in this task.

Regional and International Verification Systems

In the context of the CFE agreement and related treaties, the Western European Union (WEU) has established a regional satellite monitoring agency (RSMA) at Torrejon, Spain (officially inaugurated on 28 April, 1993) for the purpose of "monitoring disarmament treaties, crisis-management and following problems connected with the environment." In the long term, this center was designed to form the foundation of a European space-based observation system for the "maintenance of international peace and security". [ Henny J. van der Graaf, "Conventional Arms Control Verifica tion", Verification of Disarmament or Limitation of Armaments: Instruments, Negotiations, Proposals , (UNIDIR: Geneva, 1992), p.132; Western European Union, Document 1393, 8th November 1993, The Development of a European Space - Based Observation System - Part II, REPORT (1), Technological and Aerospace Committee (2)] In the initial phase, this center used images from the SPOT, ERS-1, and LANDSAT satellites, but the agency now has access to images from the HELIOS military observation satellite. In its experimental phase, the center aimed to train analysts, demonstrate the application of space imagery for treaty verification, crisis monitoring and environmental monitoring, develop computer techniques applied to interpretation of images, supply initial operational imagery products for verification, crisis monitoring and environmental monitoring. [ Jean Daniel Levi, "Policy Orientations of Space Agencies: The French Example", in Alves ed., Evolving Trends in the Dual Use of Satellites , p.153. See Alves, p.69.]

There have also been a number of suggestions for the creation of international satellite verification systems. In 1978, France proposed the International Satellite Monitoring Agency (ISMA), with the objective of searching for signs of illegal development of non-conventional weapons, preventing the outbreak of war, and supporting peacekeeping. [ A.S. Krass, "Arms Control Verification", in Arms and Disarmament: SIPRI Findings , Marek Thee, ed., (Oxford University Press: New York, 1986), pp.371 - 378; John Tirman, "International Monitoring for Peace", in Issues in Science and Technology , Vol. 4, No. 4, Summer 1988; B. Jasani and T. Sakata, eds., Satellites for Arms Control and Crisis Monitoring , (SIPRI/Oxford University Press: New York, 1987), and Krepon et al. ] In 1987, Canada proposed PAXSAT, ("Satellites for Peace") which was be comprised of two satellites. [ Alves, Building Confidene in Outer Space Activities: CSBMs and Earth to Space Monitoring , (UNIDIR: Geneva, 1995), p.68.] In 1988, the French also proposed the creation of SIPA (Satellite Imaging Processing Center), which was to be a UN agency for processing and monitoring imaging. [ Alves, p.68. More information on studies can be found in Jean Daniel Levi, "Policy Orientations of Space Agencies: The French Example", in Alves ed., Evolving Trends in the Dual Use of Satellites , p.154.] Similarly, the Middle East multilateral working group on Arms Control and Regional Security (ACRS) took up the issue of the application of such dual-use technologies for the purposes of verification and confidence building in some detail.

None of these proposals have been implemented, reflecting the limitations resulting from the political nature of such international verification systems and organizations. In addition, the impact of the distribution of data from such multilateral systems would have to be carefully considered, in order to prevent abuse for non-peaceful purposes. The negative impact of introducing a high level of transparency in a region characterized by a high level of distrust and potential conflict might be considerable, and care must be exercised to prevent such counterproductive use of overhead systems.

VI. Airborne Monitoring Applications

In the late 1980s, the increased level of democracy in Eastern Europe and the Soviet Union led to the end of the Cold War and the beginning of substantial political and economic cooperation between East and West. These changes, in turn, led to the substantial decline in the nature of the military threats faced by the states in Europe, and a series of agreements that created a cooperative security framework for Europe. The 1986 Stockholm agreement and 1990 Vienna Document of the CSCE (now the OSCE) and the 1990 Treaty establishing agreed limits on Conventional Forces in Europe (CFE) form the foundation of this security framework. In addition, the 1992 "Open Skies" Treaty established a framework for aerial monitoring and transparency among the participating states. [ Verification of Disarmament or Limitation of Armaments: Instruments, Negotiations, Proposals , (UNIDIR: Geneva, 1992); and Michael Krepon, Dominique M. McCoy, Matthew C.J. Rudolph; A Handbook of Confidence-Building Measures for Regional Security The Henry L. Stimson Center; Handbook No.1, September, 1993.] The Treaty establishes:

"a regime of unarmed aerial observation flights over the entire territory of its signatories. It is designed to enhance mutual understanding and confidence by giving all participants, regardless of size, the possibility to obtain information on military or other activities of concern to them; most smaller states will get copies of data, and are unlikely to conduct their own flights."

This Treaty is applicable to territory from Vancouver east to Vladivostok, and is the "most wide-ranging international effort to date to promote openness and transparency of military forces/activities." The principles for implementation are: complete territorial openness/access, use of unarmed aircraft for observation flights, an advanced sensor suite with sensors commercially available to all parties, and annual quotas for reciprocal overflights. The Treaty also allows for consensus decisions in the OSCC to upgrade sensors, adjust quotas, and admit new participants [ February 23, 1994, OPEN SKIES CONSULTATIVE COMMISSION, ACDA, http://www ...] .

Since the Open Skies Treaty was opened for signature on 24 March 1992, it has been signed by 27 countries in Europe, as well as the United States and Canada. The objective of the 100 page treaty is to provide a means of increasing transparency among the participating states and verifying arms control agreements, and the provisions of the CFE in particular. Nations conducting Open Skies missions must provide a minimum of 72 hours notice to the country being over-flown. The mission plan must include the desired routing and be submitted at least 24 hours prior to the flight. Optical sensors are able to detect treaty limited items to 30 cm GSD, (infrared to 50 cm, and SAR to 3 m). The treaty does not contain territorial restrictions. [ Anne M. Florini, "The Open Skies Negotiations", Encyclopedia of Arms Control and Disarmament , p. 1119. ]

As of the end of 1995, 22 states had ratified the treaty, but the failure of Russia, Belarus, and Ukraine to ratify was preventing Entry into Force, and the probability of eventual implementation decreasing. (In a vote in the Ukrainian parliament in January 1996, the Treaty did not receive enough support for passage.) [ McCausland, p.18.]

VII Analysis

The viability of space and aircraft based verification and monitoring depends on many factors, including the technical factors (GSD, spectrum, frequency, angle, etc.), the nature of the items being monitored, and the software and processing systems. Political factors are also very important, specifically in terms of the nature of relations between the states involved in the limitation agreements and the level of cooperation among them.

In cases in which the level of cooperation is low and the military threat, based on weapons capabilities (conventional as well as non-conventional) is high, the requirements for unambiguous verification are severe. In such circumstances, the degree of transparency is necessarily very limited and national technical means, including satellite sensors, are very important for assuring stability and detecting possible violations. The combination of satellite sensors and open-skies systems can be particularly effective for verification, particularly in regional settings. In its inspections of Iraq, UNSCOM has used satellite pictures, high-altitude photography, and helicopter overflights. [ Colonel Douglas Englund, "Lessons for Disarmament from the UNSCOM Experience," in Multilateral Verification and the Post-Gulf Environment: Learning from the UNSCOM Experience , Steven Mayaija and J. Marshall Beier, eds. Centre for International and Strategic Studies, York University, 1992] Although the Iraqi regime is quite unique, experience in verification technologies has been gained. As Stephen Dupree, of Sandia National Laboratories, concludes, "Monitoring systems such as those used in Iraq are not sufficient, in and of themselves, to guarantee the absence of prohibited activities. Such systems cannot replace on-site inspections by competent trained inspectors. However, monitoring similar to that used in Iraq can help deter prohibited activities and can contribute to openness and confidence building." [ Stephen A. Dupree, "UNSCOM aand IAEA: Remote Monitoring and Air Sampling in Iraq" Sandia National Laboratories, Albuquerque, June 1996]

The interpretation of the data is at least as important as the acquisition, and in many treaty verification and monitoring situations, this interpretation and analysis, based on remote sensing data, can be uncertain. [ For example, in August 1968, images indicating Soviet troop movements near Czechoslovakia did not lead analysts to conclude that an invasion was imminent, and US policy makers were reportedly surprised when this invasion took place. Similarly, after the Iraqi invasion of Kuwait in August 1990, US intelligence experts acknowledged that the preparations for this action were in evidence in US reconnaissance satellite images, but they were not recognized at the time.] In a recent attempt to use commercial satellite data to investigate allegations of Indian nuclear test preparations in the Rajasthan desert, Gupta and Pabian were unable to reach a clear conclusion regarding the accuracy of these reports. They used a variety of satellite sensing data, including declassified US reconnaissance satellite images, data from the Russian KVR-1000 cameras, SPOT-3 data, and material from the Canadian RADARSAT SAR system, but despite the availability of information from all of these sources, the analysis of space-based sensing data alone was inclusive. The implication is that for verification of the aspects of the CTBT that refer to underground testing, or for verification of potential limits on missile testing, these systems are insufficient.

As noted, this analysis was based on old reconnaissance images and more current commercial systems, and dedicated satellite verification systems can provide more consistent and less ambiguous data. In the early 1960s, the data provided by US Corona reconnaissance satellites was used to clearly show that reports of large scale Soviet missile deployment (the "missile gap") were false. Throughout the next three decades, US and Soviet satellites (NTM) monitored compliance with the SALT and ABM Treaties, and questions regarding the interpretation and analysis were relatively limited. (The question of whether the Krasnoyarsk radar system was a violation of the ABM Treaty, and similar issues, reflected conflicts over both the interpretation of the treaty ambiguity in the data.)

The resolution of such uncertainties, which are inevitable in any arms limitation framework, can be facilitated, in part, by additional technical data, greater resolution, higher frequency of observation, expert analysis, etc. However, the most important factors are based on the level of political cooperation. In the case of the US-Soviet arms control regime, the joint Standing Consultative Committee, for the ABM and SALT agreements, and the Joint Compliance and Inspection Commission, which replaced the SCC under SALT, are important political mechanisms for resolving disputes and uncertainties in the verification process.

In considering the technologies for verification purposes, it is important to recognize that the acceptable degree of transparency is inevitably linked to the nature of the relationship between the states, and the details of the limitation agreements. When the level of communication and "trust" between the states involved is very low and military capabilities and potential for conflict is high, a significant degree of transparency is not only unobtainable, but it is also destabilizing. Full openness is never possible, even in situations in which the potential for conflict is considered to be quite low, and for this reason, the existing arms limitation agreements, such as the CFE carefully balance the requirements for the transparency necessary for verification and the need for states to preseve their national security. This balance is an essential principle for regional arms limitation and verification systems of all types.

TABLE 1: RANGE AND RESOLUTION OF SENSORS [ Doyle, p.66.]

SENSOR

SPECTRAL RANGE

SPATIAL RESOLUTION

Metric camera

0.3-1.0 microns

0.3 to 1 m

Panoramic camera

0.35-1.5 microns

< 4m

Multispectral tracking telescope

0.35-1.5 microns

<2m

Multiband synoptic camera

0.35-1.5 microns

<10m

Radar imager

0.8 Ghz

10 meters x 10 meters

Radar altimeter/ scatterometer

0.4 & 0.8 Ghz

10 meters (vertical)

Wide range spectral scanner

0.32-14.0 microns

~100 meters

IR radiometer/ spectrometer

8-16 microns

~1000 meters

Microwave imager

9 Ghz

~1 km

Microwave radiometer

0.4-21 cm

3-7 kms

Laser altimeter/ scatterometer

visible

2.5 m (vertical)

Ultraviolet spectrometer/ imager

350-390 nm

<20 m (spatial)

>1 nm (spectral)

Radio frequency reflectivity

75-450 MHz

6-60 m

Absorption spectroscopy

UV, Visible, & IR

~50 m

Magnometer


~500 m

Advanced TV system

0.3-1.0 microns

~20 m

TABLE 2. GROUND RESOLUTION REQUIREMENTS FOR VERIFICATION OF TREATY LIMITED ITEMS AND DEPLOYMENTS (METERS)

Target

Detection

General ID

Precise ID

Description

Technical

Analysis

Vehicles

1.5

0.6

0.3

0.06

0.045

Communications-Radio

Radar

3

3

1

1.5

0.3

0.3

0.15

0.15

0.015

0.015

Command and Control HQ

3

1.5

1

0.15

0.09

Missile Sites

(SSM/SAM)

3

1.5

0.6

0.3

0.045

Aircraft

4.5

1.5

1

0.15

0.09

Airfield

Facilities

6

4.5

3

0.3

0.15

Bridges

6

4.5

1.5

1

0.3

Troop Units

6

2

1.2

0.3

0.15

Roads

6-9

6

1.8

0.6

0.4

Surface Ships

7.5-1.5

4.5

0.6

0.3

0.045

Coasts, landing beaches

15-30

4.5

3

1.5

0.15

Railroad Yards and shops

15-30

15

6

1.5

0.4

Ports, Harbors

30

15

6

3

0.3

Urban Areas

60

30

3

3

0.75

Terrain Features


90

4.5

1.5

0.75

Sources: Vipin Gupta, "New Satellite Images for Sale: The Opportunities and Risks Ahead", Center for Security and Technology Studies, Lawrence Livermore National Laboratory, University of California, 1994, p.2.

TABLE 3. NON MILITARY IMAGING SATELLITES

Satellite

Country

Operational

or Planned

GSD

Maximum aerial coverage over a single pass

Orbital

altitude

Effective Revisit Period at equatorial

latitudes

JERS-1

Japan

operational

18m




ALOS

Japan

planned

2.5m




ADEOS

Japan

operational

7.5m




SPOT

France

operational

10m



5 days

LANDSAT

US

operational

30m




RADARSAT

Canada

operational

20m




KVR-1000

Russia

operational

<2m


200 km

14 days

IRS-1

India

operational

5.8m




CARTOSAT

India

planned

1m




CBERS

Brazil-China

planned

20m




Earlybird

US

planned 1997

3m




WorldView

US

planned

3m

1,800 km2

470 km

4.75 days

Orbview 1

US

planned

1m

14,400 km2

700 km

2 days

Space Imaging panchromatic sensor

US

planned

1m

20,000 km2

680 km

2 days

Space Imaging multispectral sensor

US

planned

4m

20,000 km2

680 km

2 days

Sources: Vipin Gupta, "New Satellite Images for Sale: The Opportunities and Risks Ahead", Lawrence Livermore National Laboratory, University of California, 1994, p.19 , and sources cited in text.

Satellite Name

Country of Origin

Planned Use of Frequency Band

Year of Launch

ERS-1

ESA

C Band

1991

J-ER S

Japan

L Band

1992

SIR-C

USA

L,C, & X Bands

1993

ERS- 2

ESA

C Band

1994

RADARSAT

Canada

C Band

1995

Polar Platform

ESA

(TBD)

1998 ?

EOS

USA

L,C, & X Band

1998 ?

Source: Stephen E. Doyle, Civil Space Systems: Implications for International Security, UNIDIR, 1994, P.68

References and Notes: