国外研究导航系统的现状论文

Gnss是全球导航定位系统的简称，目前全球技术成熟的导航系统有GPS,伽俐略，格洛纳斯，北斗二代。其中美国的gps占主要市场，北斗二代系统后起之秀，发展迅猛，在亚太地区发展迅猛，其余两个系统由于资金投入不足，卫星更新慢，市场逐渐在萎缩。

GPS系统对抗若干分析摘要 本文阐述了GPS导航系统对现代战争的影响及导航对抗的概念，总结了GPS导航系统的发展现状、局限性，提出了针对GPS导航对抗的有效方法，并对干扰技术的可行性进行了分析。关键词 全球卫星导航系统（GPS） 导航对抗 信息对抗1 引 言现代战争的主要形式是信息对抗，信息对抗最突出的表现形式是体系对抗。在体系的同步、定位、整合过程中，GPS扮演着重要作用。当前美军GPS导航系统已经进一步现代化，精度实现了优于6m，可以说GPS导航系统是当前技术最成熟、应用最广泛、定位最精确的军民两用导航系统，更具有显著的军事导航作用，促使了美军独霸了全球军事制高点。但是，GPS导航系统本身具有很多弱点，如卫星的生存能力不强，信号强度较弱、易受干扰等，从而成为信息对抗的一个重要方面。2 GPS导航系统对现代战争的影响及导航对抗的概念导航要解决的核心问题有两个：一是被导航的平台现在处于什么位置；二是哪一条路线可以引导平台到达目的地。最原始的导航工具用的是罗盘，后来是无线电。1957年后无线电导航进入了一个新时代。GPS导航开发成功，又经过30多年的相继完善，能够在全球范围内向任意多的用户实时、连续、全天候提供高精度的坐标、速度与时间基准，为现代全球体系的目标导航带来极大的便利，对现代战争产生了深远影响：一是足够限度延长了打击距离，缩短了打击时间。GPS系统实时测距，用户接收机无源工作，一个能移动的武器打击平台，只要燃料足够，加装GPS接收机后就能够飞向世界的任何一个角落。二是极大降低了打击成本。一个GPS制导的武器打击平台，在防区外发射，可以精确命中目标，误差只有1～2米，大大节省了打击成本。三是提高了战场的指挥效率。依赖GPS的正常运作与武器GPS定位仪，战场实现了时间同步精确与机动控制有序。四是突破了战争的时间跨度。GPS系统全天候提供数据，不分白天黑夜，无论天晴下雨，增加了武器打击的突然性。随着“信息对抗”的提出，出现了导航对抗概念，它是信息对抗的延伸与发展。美军最先提出“导航战”的概念：在战场环境下，保证己方充分、可靠地利用卫星导航定位，同时阻止敌军利用卫星导航，但以基本上不使民用卫星导航受影响为条件。导航对抗的终极目的是争夺导航资源控制权，基本要素是保护和阻止，基本内涵是：1）绝不容许用提高精度的GPS导航来针对自己的部队或国家利益；2）使对方不能使用GPS与自己对抗；3）保证民间使用GPS时受到的破坏或精度降级达到最小程度；4）保证友军、盟友能接收同一系统信号。

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GPS1. SpaceThe space is part of GPS satellite by 24 work [1], it is located above the surface of the 20 200km, evenly distributed in six track surface (4) each track surface, orbit for 55 ° Angle. In addition, there are four star orbiting satellites active backup. The distribution of satellite in global anywhere at any time can be observed in 4 above, and can keep good satellite positioning accuracy of geometrical image solution. This provides a continuous on time in the global navigation skills. GPS satellite produces two groups, one group called Morse code (C/A Coarse/Acquisition Code11023MHz), A group called the P (Procise Code 10123MHz), P Code for higher frequency, not suffer interference, high precision, so by the . military control, and the password, generally, mainly for folk cannot . military service. C/A code for measures to lower accuracy, and deliberately used mainly open to . The ground controlThe ground control station by a master, five global stations and 3 ground control station. There are equipped with precision of the station clock and continuous measuring cesium visible satellites to accept machine. The satellite observation stations will obtain data, including the ionosphere and meteorological data, after initial treatment, to master station. Master station from various stations, satellite tracking data calculated the orbit and clock parameters, then will result to 3 ground control station. The ground control station in each satellite run over to the navigation, master station instructions and data into a satellite. The injection of each star GPS satellite, and in every time inject stood range from satellite before finally injection. If a ground fault, so in the satellite navigation of stored information can also be used for a period of time, but the navigation precision will gradually . User equipment partsUser equipment parts namely GPS signal receiver. Its main function is to capture by certain Angle of satellite deadline to choose to follow these satellites and satellite, the operation. When the receiver to capture the satellite tracking, after receiving antenna can be measured and satellite pseudo distance and the distance change, satellite orbits parameters, such as the demodulation data. Based on these data, the receiver can handle the computer by positioning solution method and computing the user's position in the longitude and altitude geographical position, speed, time, etc. The hardware and software receivers in GPS data post-processing software package and form a complete GPS user equipment. GPS receiver unit and receiving antenna structure is divided into two parts of the unit. Receiver generally USES machine and together two kinds of dc power supply. Setting machine aims to replace the power supply without interruption continuous observation. In use within the time machine power battery charging automatically. After shutdown, machine battery power for the RAM, memory, in order to prevent the loss of data. At present various types of accept machine, weight and small volume and light, facilitate the field Ground control system (by now), the Station so the control Station (Master), so now the Antenna (Ground), the Antenna control Station, colo springfield, Colorado (are). The ground control station is responsible for collecting information by satellite, and alex, relative to star satellite data from the atmosphere correction. Secondly, the existing users receiver for two and two, double-frequency due to price factor, general user buys more for single-rate at the application of GPS road engineeringThe application of GPS in road construction, is mainly used to establish various road engineering control network and determination of the control points electricity, etc. Along with the rapid development of the highway to survey technology, puts forward a higher request, due to long, known points less, therefore, with the conventional measure method not only, and the net difficulties are hard to meet the requirement of high precision. At present, China has gradually establish lines using GPS technology, then head high precision control network layont wires with conventional methods. Practice has proved, in a few tens of kilometers within the scope of the point error only 2 centimeters, reached the conventional method to realize the accuracy, but also greatly ahead of time. GPS technology also applied to the control measure of large bridge. Since it is unnecessary to tong, can form strong nets, improve accuracy of inspection, via conventional measure fulcrum is effective. GPS technology in the measurement of the tunnel has broad prospect of application, GPS, reduced need through conventional method, the intermediate links, therefore, high speed, high accuracy, significant economic and social GPS navigation and traffic management in automotive applicationsThree-dimensional navigation is the primary function, GPS, ships, aircraft and ground vehicles pacers can use GPS navigation device for navigation. Car navigation system is in the global positioning system (GPS developed on the basis of a new technology. Car navigation system by GPS navigation, self-discipline, navigation and microprocessor, speed sensor, gyro sensor and cd-rom drives, LCD display. GPS navigation systems and electronic map, radio communication network, computer vehicle management information system, combining can achieve vehicle tracking and traffic management and many other GPS in long-distance passenger vehicle management application (for example),In the first set of professional long-haul GPS vehicle management system, and long-distance communication GPS intelligent management system, for example, it is combined with the satellite positioning technology, GPRS/CDMA communications business, GIS, image collection technology, computer network technology, and database in the company to build a passenger control (C/S structure and B/S structure combining), and the other for points, the public security bureau and control YunGuan departments and departments of the control system, established by the control center system, wireless communication system platform (GPRS/CDMA), global positioning system (GPS), four parts and trackside equipment all-weather, a full range of driver and vehicle tracking management platform, System can be registered vehicle dynamic tracking and monitoring implementation, pictures, driving record, management, data analysis and so on the function, monitoring vehicles in electronic map, and display of vehicles running track data, Operating terminal optional internal network or the Internet server to visit and through the center to provide online IE browser integrated passenger management data analysis of the control system (B/S structure), And the capacity of the system software available according to the center of the hardware configuration and operating terminal server, the most greatly expanded, net vehicles 500,000 can not only is long, can the passenger vehicles such social vehicles. And the system still can use group management, different types of vehicles into different groups, facilitate the operation technology application examples in the navigatorGPS navigators international leading brand: Ahada YiHang (of) -- from silicon valley, now login China!The core products function:1) map queryA penny saved is a penny gained in operation on a terminal search your destination penny saved is a penny gained can record you always want to place, and retain information, also can be Shared with others and the location penny saved is a penny gained fuzzy query your attachment or a location near the station, hotel, such as ) route planningA penny saved is a penny gained GPS navigation system will be set according to the starting point and destination, automatic programming penny saved is a penny gained planning routes whether can be set to pass some penny saved is a penny gained planning routes whether can avoid high-speed etc. ) automatic navigationA penny saved is a penny gained speech navigation:To provide drivers advance in speech, navigation condition intersection traffic information, such as a way to understand the wizard tells you how to drive to the destination. Navigation in one of the most important function, make you need, through watching operation terminal voice prompt can safe penny saved is a penny gained picture navigation:In the end, will display operate maps and position of the car now, driving speed, the destination of the route, planning, crossing the road to penny saved is a penny gained redesign line:When you have the line planning, or go wrong when crossing, GPS navigation system according to your present position, for you to plan a new route to the principleGPS navigation system is the basic principle of measuring the satellite to known position of the distance between the user receiver, and then integrated satellite data can know the location of the receiver. To achieve this objective, the position of the satellite can according to record the clock time on satellite star found in a calendar. Visible GPS navigation system is part of the satellite launch navigation ceaselessly. However, due to the use of the user to accept machine with satellite space-borne clock clock synchronization, may not always except user 3d coordinate x, y, z, will also introduce a Δ t is the difference between the satellite and the receiver as unknown, then use four equations will these four unknown. So if you want to know, the receiver's place at least four satellites can receive the receiver can receive the GPS clock can be used to accurately on the two levels of second time information, Used to forecast the next few months in the general position of satellite prediction star alex, Can be used to calculate the location for the satellite radio star alex, the coordinates for a few meters to dozens of accuracy of each different, rice (change) satellite, And the GPS system information, such as receiver to code measurement can get satellite receiver, because of the distance to the clock contains receiver satellite transmission error, error and the atmosphere is called pseudorange. 0A yards of measured pseudorange called UA yards pseudorange and accuracy for about 20 meters of P yards, measured pseudorange called P yards pseudorange and accuracy for about 2 receiver of received signal, decoding technology, or other information on the carrier modulation in removed, can restore carrier. Strictly speaking, the carrier phase should be called the carrier frequency phase, it is patted the received by doppler frequency influence of satellite signal receiver carrier phase and machine generated signal phase difference oscillations. General bell in the epoch receiver determined to keep time measurement, satellite signal, it can track record of phase change, but start when the value of the receiver and satellite observations of the oscillator is not know the initial phase of the epoch, also don't know phase integers, namely the fuzzy degrees, only in data processing as parameters. Phase observations of high precision and mm, but the premise is a whole week, so only in fuzzy relative positioning, and a continuous observation can use phase observations, and to achieve superior level meters positioning accuracy of also only using phase to the localization way, GPS positioning and relative into single point positioning (difference). According to a single point positioning receiver is the observation data to determine the position of the receiver, it only USES pseudorange observation, can be used as a compendium of navigation and positioning vehicles. Relative location (difference) is based on the observation data of two above receiver to determine the relative position between the observation methods, it can be adopted pseudorange observation may adopt phase observation and geodesy or engineering measurement shall be made phase observation value relative the GPS observation satellite and the receiver is contained in the clock, atmospheric propagation delay, the multipath effect etc, in the positioning error when calculating by satellite radio star alex, the influence of error in relative positioning error when most public offset or weakened by positioning accuracy, so will greatly improve, double-frequency receiver can according to the observation of two frequency offset the atmosphere, the main part of the error of the ionosphere, high accuracy in the distance between the receiver when significant difference (air), should choose double-frequency receiver.