AN OVERVIEW OF GPS
The GPS system, which was built by the US DoD, cost more than $10 billion to construct. It consists of three primary components: the space, control, and user segments. The space segment consists of 24 satellites in six inclined, low earth orbits, 20,200 kilometers above Earth. The control segment consists of ground monitoring stations around the globe operated by DoD. The user segment is any receiver that can acquire GPS signals from the satellites. GPS satellites carry atomic clocks that continuously transmit precise time signals. The system can determine a receiver's position anywhere on Earth and low Earth orbit by recording the length of time taken by the satellites' coded radio signals to reach the receiver, which itself generates a set of codes identical to those of the satellites. The travel time is multiplied by the speed of light to determine the receiver's distance from the satellites. At least four satellites, whose positions are always known, must be overhead in order for GPS to determine the three-dimensional position of a receiver relatively accurately.
GPS satellites transmit two types of signals. The first is the precision (P)-code, which provides the Precise Positioning Service (PPS), and requires a decryption key to access. Primarily confined to US military use, this signal will allow a receiver to determine position with an accuracy of about 21 meters. The second signal GPS produces is the coarse acquisition (CA)-code. First available for civilian use in 1984, this signal provides what is known as the Standard Positioning Service (SPS) for worldwide access via a standard, commercial GPS receiver. Historically, DoD deliberately degraded this signal by a technique called selective availability (SA). When SA is operating, DoD deliberately introduces random errors into the signal, resulting in positioning errors, and a CA-code accuracy of 50 to 100 meters. The military employed SA for fear that adversaries could use a more accurate signal to the detriment of the United States. Clinton's 1996 GPS policy called for SA to be shut off permanently by 2006 at the latest. On May 1, 2000 President Clinton announced that the government would stop degrading the civilian signal with SA in order to enhance the signal's everyday usefulness. ² Thus, at midnight on May 1, 2000, SA was turned off, and GPS's accuracy dramatically increased. With SA off, the accuracy of a commercial GPS receiver is now between 6 and 15 meters. ³ The military retains the ability to deny GPS signals regionally if deemed critical to national security. The United States plans to add two additional signals to future GPS satellites to enhance the system for civilian aviation and maritime navigation and scientific use, although Congress did not approve GPS civilian signal upgrades for 2000. ⁴ Despite difficulties in obtaining Congressional funding for GPS, some funds have been allocated to GPS improvements through FAA and Department of Transportation appropriations. ⁵
Augmentation systems can improve the real-time accuracy and availability provided by SPS. One method, known as differential GPS, or DGPS, can provide augmentation of the basic GPS signal on both local and regional scales. DGPS improves positioning accuracy of a user's receiver by using additional receivers in precisely known locations that receive GPS signals and transmit a correction signal to the user's receiver at a different frequency. DGPS thus corrects for the effects of SA and other system errors, making GPS more accurate and reliable. Many countries and private companies operate DGPS correction networks. In areas in which differential GPS systems operate, commercial GPS receivers are now accurate to 1 meter or better. ⁶ Private service providers operate their own, fee-based DGPS networks to serve high-precision applications such as mining, forestry, transportation, and surveying. The government, via the Coast Guard and the National Geodetic Survey, maintains two DGPS networks for maritime and geodetic purposes. The FAA is also developing a Wide-Area Augmentation System (WAAS) and Local-Area Augmentation Systems (LAAS) to support air traffic management. ⁷ While the existing networks are based on the ground, WAAS will be a space-borne system providing DGPS corrections over large areas of North American airspace.
GPS has multiple beneficiaries. The US military, its creator and primary intended user, has integrated GPS into almost every facet of its operations, ranging from the positioning of troops to navigation over air, sea, and land to precision timing and targeting of guided weapons. The civil sector worldwide is increasingly using GPS for public services including emergency response, search and rescue, weather forecasting, highway construction, land management, and air navigation. GPS is also useful to surveyors, motorists, farmers, hikers, and geology and environmental researchers. GPS is not only a powerful technology, but also a profitable one: in 1998, the sale of GPS-based goods and services grossed $4 billion in worldwide revenues, and this market is projected to grow annually by 25 percent through 2003. The United States is a world leader in the GPS equipment and service industry, and currently holds one-third of the market. US companies are projected to maintain this dominance for the next several years. ⁸ Now part of the emerging Global Information Infrastructure, GPS use reduces the costs of a variety of civilian and military navigation and positioning activities by improving efficiency and accuracy for no more than the cost of a receiver.
GPS is not the only existing RNSS. The Russians operate a counterpart system known as GLONASS, which stands for the Global Orbiting Navigation Satellite System. While 24 satellites are required to provide precise navigation information worldwide, only ten GLONASS satellites are currently functioning. These ten satellites provide good coverage in Russia, and parts of Europe and Asia, but not worldwide. GLONASS's deterioration is a result of Russia's poor financial situation. When fully functional, GLONASS provides better positioning accuracy than GPS's CA-code with SA turned on. GLONASS, which possesses no SA feature, operates at different frequencies and uses different position algorithms than GPS. Thus, the two systems require different operating equipment. GLONASS, like GPS, is owned and operated by the Russian military, and has its own version of GPS's P code. Because GLONASS supports the Russian military, the nation has a strong incentive to keep the system operating. In order to attract funding for GLONASS, Russia has offered to let the system be the basis of an international navigation system and has also negotiated funding and use arrangements with various countries. ⁹ Russia launched two GLONASS satellites in October 2000. At least 15 more satellites need to be launched in the next few years to keep the system operational.
Europe is in the process of developing an independent, global satellite navigation system, which will, if completed, be called Galileo. ¹⁰ The European Space Agency (ESA) and the European Union (EU) are working together to build this system. Europe's increasing dependence on foreign-owned RNSS systems led to the desire to develop Galileo, "an independent system under civilian control which will be guaranteed to operate at all times." ¹¹ The Galileo system will be made up of 30 satellites (27 active satellites, and three spares), and will be interoperable with GPS and WAAS in Europe, Japan, and the United States, as well as with Russia's GLONASS. Unlike GPS and GLONASS, Galileo will be civilian owned and operated. Galileo will ensure European access to RNSS, enable improved aircraft guidance and positioning, provide better coverage in northern Europe, bolster Europe's RNSS-related industries and create new jobs in the aerospace and information industries. ¹² Currently in development, European officials expect Galileo to be fully operational by 2008, with some limited operability by 2006. In April 2001 Galileo moved closer to becoming an operational reality when EU transport ministers agreed to "an initial 100 million euros ($87 million) in funding for the 30-satellite Galileo constellation." ¹³ The EU and ESA are providing initial funding for Galileo but are trying to attract private investment in the system. The system's basic service will be available worldwide free of charge, although the EU may impose a tax on GPS receivers, or provide enhanced, fee-based services in order to earn revenue.

RNSS AVAILABILITY IN THE PACIFIC RIM
The use of RNSS varies widely within the countries under examination in this paper. The following sections summarize the uses of RNSS in each country. Table 1 provides an additional overview.

• JAPAN
  Of the five Pacific Rim nations examined here, Japan is most involved in RNSS commerce, applications, and infrastructure. Although Japan uses GLONASS to some extent, the majority of the nation's RNSS activity centers on GPS. GPS commerce is big business in Japan: the country is Asia's leading GPS equipment manufacturer and had the highest world market share in 1998 with 47 percent. ¹⁴ Japan is particularly renowned for having the world's largest portable and automobile GPS receiver industry. ¹⁵ These products are widely used domestically and abroad, both within and beyond Asia. Thus, the Japanese economy reaps large benefits from commercial enterprise based on GPS. The Japan GPS Council, the counterpart of the US GPS Industry Council, helps promote the Japanese GPS industry, with both government and private support.
  Japan relies heavily on GPS applications for military and civilian applications. The nation is one of the world's largest users of GPS military equipment; military-grade GPS receivers and encryption devices are extensively used by Japan's Maritime Defense Forces. ¹⁶ In addition, the Japanese Defense Agency has an agreement with DoD to access military-level GPS signals. ¹⁷ GPS receivers are also used in Japan for maritime navigation in coastal areas, aircraft navigation, surveying, and monitoring crustal motion and volcanic activity. ^18,19,X20
  Japan also makes extensive use of DGPS correction networks. The Japanese Maritime Safety Agency operates a maritime beacon DGPS network for safety in coastal navigation. A private DGPS service provider uses a network of 34 ground stations to cover nearly the entire island nation. ²¹ Two civilian agencies in the Japanese government are also making efforts to build a wide-area DGPS network for international aviation safety. ²² Called the Multifunctional Transport Satellite (MTSAT), this space-based augmentation system is intended to supply DGPS correction data to improve the accuracy of GPS-based navigation data for Japan's flight information region. The system will also have some meteorological applications, but will not have any signal encryption for military uses. Japan attempted to launch an MTSAT in November 1999, but the H-2 rocket carrying it was destroyed when it deviated from its flight path. As safe air traffic management is critical over the increasingly crowded skies of the Asia-Pacific region, Japan is likely to persist in its attempt to orbit an MTSAT.
  While Japan has undertaken significant efforts to create national DGPS networks, and possesses a strong GPS-based industry, and myriad GPS applications, the nation has no independent RNSS and is unlikely to develop one in the near future. In March 1997, Japan's Science and Technology Agency looked at five ways the nation could proceed in satellite navigation, ranging from developing an independent RNSS for the region, to continuing to rely on GPS and GLONASS, to cooperating with Europe on an RNSS. The agency decided to continue research into satellite navigation technologies that could, if desired in the distant future, lead to the development of a Japanese RNSS. The Japanese decision not to pursue an independent RNSS project resulted from the high costs of such an endeavor, a focus on capturing the ground-equipment markets, and to US concerns that such an undertaking would undermine GPS. ²³ Thus, Japan has focused its primary efforts on creating GPS augmentation systems, and cooperating on the development and funding of an RNSS with Europe. Japan has also considered paying for part of upgrades to GPS or a next-generation system led by the United States as long as Japan could contribute hardware. ²⁴ In 1998, the Japanese government signed a cooperative statement with the United States declaring its commitment to work with the United States to promote GPS as a worldwide standard for navigation, positioning, and timing. ²⁵

• CHINA
  China has been increasingly involved with, and interested in, RNSS. GPS and GLONASS are both used for a variety of applications. Civilian uses of the systems include dam construction, coastal navigation, police dispatch, cargo monitoring, surveying of oil and gas reserves, and air traffic management. ²⁶ China also uses GPS and GLONASS for military applications. ²⁷ The Chinese aerospace industry is currently integrating GPS into its new fighter aircraft, while the military has used GPS technologies to support unmanned aerial vehicle programs and field training exercises. ²⁸ China has also expressed interest in using GPS and GLONASS to increase the accuracy of ballistic missiles through mid-course guidance corrections. ²⁹ Currently, China has some domestic GPS and GLONASS receiver production capabilities, but is not a major developer or manufacturer of RNSS user technology. There are reports, however, that the Chinese military-industrial complex has entered into joint ventures with foreign firms to produce GPS receivers for possible incorporation into weapons. Such weapons could be used by China or sold to third parties- including "nations of concern." ³⁰ China's military uses of GPS are a concern for the United States and its allies. Nevertheless, the Chinese are unlikely to rely heavily on RNSS and RNSS applications for military purposes until they have their own RNSS system and/or guaranteed access to RNSS.
  China currently has limited indigenous RNSS capabilities, and operates several DGPS ground stations for activities such as air traffic management. China has stated an interest in developing a space-based navigation capability, and has engaged in navigation satellite research for at least 20 years. It recently launched a two-satellite regional positioning satellite system called Beidou ("Northern Dipper"). The two geostationary satellites, launched in October and December 2001, are less capable than GPS or GLONASS, but give China its first autonomous satellite navigation capability. ^31,32 Chinese officials have stated that China is working on a more complex, global navigation system using a larger number of satellites in various orbital planes. ^33,34 Most recently, the Chinese have expressed interest in helping Russia fund GLONASS. ³⁵ China can be expected to seek to depend on RNSS systems other than GPS, although the Chinese are also likely to continue using the US system. China finds RNSS an increasingly useful and necessary tool, but is reluctant to increase its dependence on foreign owned systems, especially if such systems are owned and operated by non-Chinese military services.

• TAIWAN
  Taiwan has only recently become involved in space activities. In 1990, Taiwan established a National Space Program Office to develop basic space technologies and satellites for purposes such as communications, environmental monitoring, and scientific research. Taiwan also hopes to create an indigenous space industry for national security and economic growth; however, its use of RNSS is currently minimal, especially compared to Japan and China. Taiwan has begun limited use of GPS technologies to support missile, fighter aircraft, and unmanned aerial vehicle programs. ³⁶ On the civilian side, research institutes and universities use GPS technology for mapping, surveying, and geodesy. In 1989, Taiwan established a GPS receiver network to monitor ground movement, which, in this earthquake prone island, remains the chief GPS application. Taiwanese commercial investors have begun to finance the development of autonomous vehicle navigation systems as well as computer software based on GPS. In the near future Taiwan's main involvement with RNSS will be in GPS augmentation, civilian and military GPS applications, and development of commercial GPS products. Taiwan does not have the resources to develop its own satellite navigation system.

• NORTH KOREA
  North Korea's most widely known and worrisome use of RNSS is for military applications. The DPRK has reportedly used GPS receivers imported from Japan on its submarines. Reports have also indicated that North Korea leased a Thai communications satellite equipped with GPS to plot the path of a missile it planned to test in August 1999. ³⁷ Some analysts worry that North Korea may soon integrate GPS receivers into its indigenous or imported medium- or long-range ballistic missiles to improve their accuracy. ³⁸ North Korea has declared its intentions to use space capabilities for peaceful purposes, but has also stated that it would use these assets for military ends if confronted with foreign hostility. Despite its intention to be an independent space-faring nation, without dependence on China or any other nation for access to space, the primitiveness of North Korea's space technology and the poor condition of its economy make it highly unlikely that North Korea will develop its own RNSS. ³⁹ The US policy considerations regarding North Korea and RNSS should include possible North Korean hostile use of GPS and other available RNSS, including procurement of RNSS receivers and RNSS-responsive weapons from other countries, incorporation of GPS technology into its own missiles, and development of GPS spoofing or jamming capabilities for use in regional conflicts involving North Korea.

• SOUTH KOREA
  South Korea makes fairly extensive use of GPS for a variety of civilian applications, including maritime and aviation navigation, land surveying, bridge construction, precise synchronization of telecommunications networks, and intelligent transportation. ⁴⁰ The size of the domestic market for GPS equipment and services is unknown; however, private firms in South Korea manufacture GPS receivers for handheld and automobile navigation uses and also offer GPS-based services. ⁴¹ As of 1997, the nation planned to build a DGPS correction network. ⁴² While various government ministries and agencies oversee the use of GPS, the Korea Astronomy Observatory monitors the local quality of, and any interference in, GPS signals. South Korea is seeking to develop both an indigenous space launch capability and a satellite-manufacturing industry. ⁴³ Given its alliance with the United States, and the expense and difficulty of building an indigenous RNSS system, South Korea is likely to forgo developing its own system, and continue to use GPS. South Korea may develop a regional DGPS network to augment the GPS signal, sustain GPS-based applications and commercial activity, and possibly use other countries' RNSS. ⁴⁴