Interference and deception detection technology of satellite navigation based on deep learning

The “youngest” of the major satellite applications is the field of satellite navigation. This field of measurement and ranging through the use of satellite positioning systems first started in the context of scientific research. This initial use of satellites was simply for positioning and location. These activities, that were first based on using Doppler frequency shifts as a satellite orbited above, were largely scientific and not strategic. These types of activities included geodetics (i.e., such as the measurement of continental drift over time) or the collection of scientific information and data from atmospheric landor ocean-based sensors where the specific locations of the sensors were important. The real strides in the development of satellite navigation, however, came when space systems were developed for the specific purpose of precise targeting of missiles and various other types of weapon systems. The Soviet Union/Russian J.N. Pelton (*) International Space University, Arlington, VA, USA e-mail: joepelton@verizon.net S. Camacho-Lara Centro Regional de Ensenanza de Ciencia y Tecnologia del Espacio para America Latina y el Caribe (CRECTEALC), Santa Maria Tonantzintla, Puebla, Mexico e-mail: sergio.camacho@inaoep.mx # Springer Science+Business Media New York 2016 J.N. Pelton et al. (eds.), Handbook of Satellite Applications, DOI 10.1007/978-1-4614-6423-5_10-3 1 Federation satellite navigation system, known as GLONASS, and the US-based Navstar system –with its Global Positioning Satellite (GPS) network – developed space-based systems that provided unprecedented capabilities to determine locations on the ground or oceans with great accuracy. Early systems such as Argos that relied on Doppler shift technology were only accurate within a precision of hundreds of meters. Today’s advanced satellite navigation systems, however, are accurate for measurements that can be indicated with a precision only a few meters and within centimeters if utilizing reference stations. The fact that GPS and GLONASS satellite signals are freely available in space for all to use has spurred the development of low-cost receivers for much more than strategic or military usage. Today, various types of civilian use of navigational and positioning satellites have become popular on a global basis. The latest development in application-specific integrated circuit (ASIC) chip technology has fueled the growth of applications based on the use of these precise spacebased navigational and positioning systems. The availability of these highly capable but increasingly low-cost chips – small enough that they could be included in handsets such as cell phones or included with the electronics available on various types of vehicles (i.e., cars, trucks, buses, trains, airplanes, ships, etc.) – represented a real breakthrough. The development of specialized computer chips to perform satellite navigation calculations has increased the number of users of this technology from a relatively small population of several thousands to tens of millions. In the coming decade, the proliferation of international satellite navigation systems in orbit (i.e., USA, Russian Federation, China, India, Europe, and Japan) plus the continued development of ever lower cost of satellite navigation chips for receivers will continue the popular expansion of these increasingly “easy to use” and versatile systems. Wide and easy access to low-cost consumer receivers for satellite navigation services strongly suggests that this trend of expanded use will continue to surge. Thus, within a decade, use of these devices will increase to the hundreds of millions if not billions of people. Atomic clocks with incredible temporal precision today allow satellite navigation systems to be used by military organizations, governmental geospatial scientists, and scientists to determine locations with great accuracy. But these applications are now just a small fraction of total usage. The deployment of the new international satellite navigational systems and smaller and lower cost ground receivers will support an ever-increasing civilian consumer market for an ever-expanding range of everyday applications. These consumer applications include driving a vehicle to a desired location, safely sailing a boat, going mountain climbing or hiking without getting lost, or simply finding out where you are within a city. The precise time keeping ability of today’s satellite navigation systems also means that these spacecrafts can also serve as a global timekeeper for computers and scientific experiments. The time stamp from a satellite navigation satellite can also be used not only for scientific or regulatory purposes but for other applications such as security and banking systems as well. These satellites are also used to support the synchronization needs of communications satellites. In short, 2 J.N. Pelton and S. Camacho-Lara

During the course of studying how to improve and optimize the anti-jamming ability of the satellite navigation and positioning system, the satellite channel was faced with many types of jamming signals. It is difficult to adopt one kind of jamming suppression technology to effectively suppress all kinds of jamming. In order to solve these problems, a new anti-jamming architecture for satellite navigation and positioning system is proposed. That is adopting the jamming cognitive method combined with the time-frequency domain jamming type recognition, power analysis and jamming DOA estimation. Also, the anti-jamming architecture design of the satellite navigation and positioning system is given based on the jamming cognition. Theoretical analysis and simulation results show that the anti-jamming architecture can detect the different jamming signals according to different jamming types, simplify the jamming suppression algorithm, grade and classify to suppress jamming signals.

Navigation signals are the basis of satellite navigation systems, which determine the navigation systems' performance (such as tracking accuracy, anti-interference capability etc.), and are determined by some constraints (such as radio frequency resources, construction cost, technology level etc.). The aim of signal design is to select "proper" signals considering these above factors and make tradeoffs between performance and constraints. This paper will summarize the signal structure evolution of present satellite navigation and conclude some principles and issues which will be greatly valuable to our 2nd satellite navigation system. There's four main satellite positioning systems presently, the U.S. Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS), the Europe Galileo satellite navigation system and the Chinese BD-1 satellite positioning system. Among these systems, the signal characteristics of GPS and Galileo are good reference to our 2nd satellite navigation system. The improvement of GPS signals is a main aspect of GPS modernization. The aim of GPS modernization is mainly to modernize its signal structure so as to improve the whole systems' performance. The signal structure of Galileo has been revised for several times, and its present signal is the results of long time signal design. From GPS modernization and Galileo signals status, we can summarize some key specifications of navigation signals and some technologies to support these specifications. Based on this, we'll discuss some problems which should be attentive in our country's 2nd satellite navigation system and give some suggestions. This paper is organized into five sections. The first section will give a brief introduction of present satellite navigation system and their main features. Section two will review the GPS and Galileo signals structure evolution, including GPS modernization, Galileo signals status and the comparison of two systems' signals. In the third section, the relationship between signal parameters and system performance will be analyzed, including RF signal characteristics, modulation type, ranging code (such as code type, length and rate) and navigation data. In section four we will discuss some inspiration and technologies concerning our 2nd satellite navigation system, such as the use of multiple frequency signals (ionospheric delay estimation and carrier ambiguity resolution), pilot tones & dataless channel, binary offset carrier (BOC) modulation, and so on. The last section is conclusion, in which the whole paper will be retrospected and some useful conclusion will be given.

Methods of the actual values of the angles of attack and slip determination in the technology of air data systems estimation using satellite navigation systems during aircraft flight tests of are stated. Also methods of parametric identification of mathematical models of on-board aerodynamic angles measurements errors are presented. The technology has been developed and implemented in the practice of flight tests at Flight Research Institute. The technology shows high efficiency of solving tasks of air data on-board systems, vertical separation systems, flight performance and takeoff and landing characteristics estimation in flight tests. The technology covers a wide range of issues of aerometric measurements, many of which have already been published. Here, attention is paid to measurements of aerodynamic angles. The features of determining the angles of attack and slip using data from air data systems, satellite and inertial navigation systems are shown. Equations for determining the angles of attack and slip during testing, factors of measurement errors, the structure of the mathematical model of the aerodynamic errors of the angle of attack on-board measurements are presented in a stationary approximation. Algorithms for solving problems in steady and unsteady modes of flight, takeoff and landing are considered. The completeness of the solution for the wind speed vector is noted. Estimates of methodological errors in determining aerodynamic angles using the technology are made. Compliance with modern requirements is showing. The effectiveness of the technology is confirmed by the materials of flight tests of a short-range aircraft. Typical examples of test materials presentation, features of measurements depending on the type of test mode, aerodynamic influence factors are shown.

To date, the United States, Russia and the European Union have promulgated or amended legislations, presidential decrees, administrative regulations and directives concerning the issue of satellite navigation, forming a relatively comprehensive administrative and legislative system. By delineating the executive missions, operation mechanisms and procedures for the satellite navigation sectors in the respective states, such system has laid a solid foundation and provided legal guarantees for the development of their satellite navigation systems. In China, there have already been some national, state-departmental and provincial policies and regulations of similar targets, such as National Satellite Navigation Industry Mid-term and Long-term Development Plan; however, insufficiencies in the legislative and administrative system of China’s satellite navigation development still exist, namely, a lack of top-level laws or regulations, arbitrariness in policies, uneven organization of the policy structure, and imbalance of policy subjects. By applying the approach of quantitative research, this article conducts a systematical summary and analysis of the regulations, laws, and political documents concerning satellite navigation in China and to explore the transformation process and diffusion of the policies, as well as the relationship between the authorities involved. In so doing, it aims at figuring out the kernel problems of the political and legislative system of the current satellite navigation in China and putting forward corresponding solutions to them, including the need for an improved system with timely top-level policies, the need for the promotion of industrial development and optimization of the policy structure, and the need for a coordinated relationship between policy subjects and a guarantee for the implementation of policies.

Navigation systems for ships mainly include inertial navigation system (INS), “BeiDou” satellite navigation system, Global Positioning System (GPS), and Doppler navigation system and so on. The characteristics of each system are different. In order to improve the accuracy and fault-tolerant ability of naval-ship navigation system, an integrated navigation algorithm based on Measurement-based adaptive Kalman filtering algorithm (MAKF), improved Suge-Husa algorithm and non-reset federated Kalman filter structure is proposed in this paper. The algorithm uses the short-term high precision of the inertial navigation system and the prior velocity information of the ship to adaptively estimate the measurement noise characteristics of the satellite navigation system. When the satellite navigation system is unable to locate, the INS and the log are combined with the help of the prior velocity information. The simulation results show that the algorithm can effectively exploit the characteristics of each navigation system, and can output high-precision navigation results even when the GPS/BeiDou satellite navigation system fails.

New progress of navigation and positioning technology, especially satellite navigation and positioning technology is reviewed in this paper. Development trend and direction of satellite navigation technology after GPS is discussed. Compatibility and interoperability of multi-mode satellite navigation system, integration and complementarity of satellite navigation with ground mobile network, and the integration of navigation and communication technology are introduced respectively in the first place. Then the inbound satellite positioning and communication system and bi-directional satellite positioning communication system are proposed. Finally, the possibility of the integration of navigation signal and function into the communication link is looked into the future.

The sidewalk is often located in complex environments such as buildings or covered by dense trees. Satellite navigation systems are susceptible to the surrounding environment, resulting in multipath effects, resulting in reduced positioning accuracy. Therefore, the global satellite navigation system (GNSS) and inertial navigation system (INS) based on kalman filter (KF) algorithm are studied, and the navigation algorithm and system model suitable for pedestrians are given. Considering that the pedestrian speed is low, the satellite navigation system obtains the carrier orientation information (heading angle), which also produces a large error. Therefore, the pedestrian dead reckoning (PDR) correction method is adopted to make the positional accuracy of the integrated navigation continuously stable. This paper proposes a pedestrian navigation system solution based on a single navigation device.

Nowadays (June 2014) two satellite navigation systems (SNS), GPS and GLONASS, and four satellites based augmentation systems (SBAS), EGNOS, WAAS, MSAS, and GAGAN are fully operational, two next SNS, Galileo and BeiDou, and one SBAS, SDCM, are under construction. This paper gives the reply to some important questions as: these final numbers of the SNS and SBAS, four and five respectively, will be sufficient for all users in the whole world at any time or no; which user, why, where and when needs apart from GPS system the new SNS and next SBAS; which way the problem of compatibility and interoperability of all these systems will be solved; all these changes what it means for the users of different modes of transport.

Satellite navigation systems, inertial navigation systems and integrated systems (satellite navigation systems and inertial navigation systems) are used to determine navigation parameters. But satellite navigation systems are not autonomous. Although inertial navigation systems are autonomous, they accumulate errors over time that require external correction. A new method of autonomous determination of latitude and longitude of moving objects is proposed. Unlike standard methods, this method does not use double integration of accelerometer signals. To determine latitude and longitude, gyroscope signals are used, which are part of the inertial measurement unit (IMU). To implement the method of autonomous determination of latitude, it is enough to have the signals of the IMU gyroscopes, the elements of the direction cosines matrix, the angles of rotation of the object, and their derivatives. For the autonomous determination of longitude, it is necessary, in addition, to know the initial value of the longitude. The use of the Luenberger observer to determine of latitude and longitude is considered.

Navigation parameters such as vehicle heading, linear speed and latitude and longitude are determined today, as a rule,using satellite navigation systems. However, there is a need for autonomous determination of navigation parameterswhen satellite navigation system signals are unavailable for one reason or another. For example, satellite navigationsystem signals can be jammed by electromagnetic countermeasures.Autonomous systems for determining the vehicle navigation parameters are inertial navigation systems, the basis ofwhich is the double integration of signals from accelerometers, as well as the integration of signals from gyroscopes toform one or another coordinate system, if we are talking about strapdown inertial navigation systems (SINS).Integration of the output signals of accelerometers and gyroscopes, which contain errors, leads to the accumulation ofSINS errors. To increase accuracy, SINS are integrated, for example, with satellite navigation systems. However, suchsystems cease to be completely autonomous.The article uses the method of autonomous determination of vehicle latitude and longitude, which is a new method ininertial navigation. The method is based on the strapdown inertial technology, which, unlike the standard methods usedin SINS, does not use the integration of the output signals of accelerometers and gyroscopes. To determine the angles oflatitude and longitude, the signals of the gyroscopes included in the inertial measurement unite (IMU) are used.As a result of a semi-natural experiment, the efficiency of the method of autonomous determination of latitude andlongitude was verified. Flight data of a small-sized aircraft were used for experimental verification. The data containedinformation about the angles of the heading, pitch, roll of the aircraft, the output signals of three micromechanicalgyroscopes, three micromechanical accelerometers, information about latitude, longitude and altitude measured by thereceiver of the satellite navigation system, as well as information about the horizontal and vertical components of speedand current time. Plots of calculated values of latitude and longitude and values measured using the receiver of thesatellite navigation system are given. From the given plots and tables, it can be seen that from a certain time, thecalculated values coincide with the "reference" ones, which confirms the efficiency of the method of autonomousdetermination of latitude and longitude.

The ultra-wideband polarization converters have been of interest to researcher due to their demand in satellite communication and navigation systems. This paper presents an ultra-wideband reflective cross-polarization converter comprising a stair-shaped metasurface. By observation, the alleged structure allows the conversion of linearly polarized waves to orthogonal components, having a polarization conversion ratio of greater than 90% spread across the large frequency range of 12.94 to 16.54 GHz and 17.54 to 26 GHz. A highly efficient, ultra-high frequency polarization conversion is achieved by the utilization of strong electromagnetic resonance coupling between the upper and lower layers of the metasurface. Further, it is depicted that the polarization converter has a wide obliquity of incidence wave. Moreover, the simulation and measured results show a good match. The linear polarization converter is simple in design but is of high performance, and therefore, might be useful in satellite communication, imaging systems, and navigation systems.

Knowledge of the state of the upper atmosphere, and in particular its ionospheric part, is very important in several applications affected by space weather, especially the communications and navigation systems that rely on radio transmission. To better classify the ionosphere and forecast its disturbances over Europe, a data collection endeavour called the European Digital Upper Atmosphere Server (DIAS) was initiated in 2004 by a consortium formed around several European ionospheric stations that transmit in real-time ionospheric parameters automatically scaled. The DIAS project is a collaborative venture of eight institutions funded by the European Commission eContent Programme. The project seeks to improve access to digital information collected by public European institutes and to expand its use. The main objective of the DIAS project is to develop a pan-European digital data collection describing the state of the upper atmosphere, based on real-time information and historical data collections provided by most of the operating ionospheric stations in Europe. Various groups of users require data specifying upper atmospheric conditions over Europe for nowcasting and forecasting purposes. The DIAS system is designed to distribute such information. The successful operation of DIAS is based on the effective use of observational data in operational applications through the development of new added-value ionospheric products and services that best fit the needs of the market. DIAS is a unique European system, and its continuous operation will efficiently support radio propagation services with the most reliable information. DIAS began providing services to users in August 2006. The Need for Accurate Ionospheric Products Radio frequency communications and satellite positioning and navigation systems are applications most affected by ionospheric disturbances. Such disturbances can cause drastic and large-scale changes in the usable ranges of high frequency (HF) or below HF bands affecting standard ground-to-ground and submarine communication systems. The characteristics of an ionospheric propagation channel, whether it is HF or transionospheric frequencies, are highly variable on timescales ranging from a few seconds to the 11-year solar cycle. Even during its quietest periods, the Sun produces electromagnetic radiation and solar wind, both of which can affect a variety of geomagnetic and ionospheric phenomena, which in turn affect radio waves propagating through the ionosphere. Hence day-to-day and hour-to-hour changes in propagation channel characteristics can occur.

Understanding Satellite Navigation

X-Ray pulsar navigation is a new technology for astronavigation. It’s an effective supplement to the satellite navigation which is widely used at present. It can provide autonomous navigation services for spacecraft that cannot be covered by satellite navigation system. China has started researching on engineering application since 2005, and sent specific satellites to carry out space experiments in 2016. Compared to theoretical research and engineering application, the standardization of X-Ray pulsar navigation is left behind. There are no relevant standards and top-level planning for X-Ray pulsar navigation in the standard systems at national level. Standardization is an important guarantee condition to ensure development of an industry and progress of a major project. The general departments take standardization as an important work in the major national projects, such as CMS, BeiDou, CHEOS and so on. As an important part of navigation project, the standardization of X-Ray pulsar navigation is to meet the needs of navigation engineering construction, and is an effective way to implement the requirements of navigation standardization. This paper explains how to carry out standardization by combining the technical characteristics and development status of X-Ray pulsar navigation.