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1.
卫星着陆系统(GLS)作为先进的航空新技术,其主要功能是为终端区精密进近的机载设备提供信号修正增强服务,为实现整个系统高精度离场和精密进近的功能发挥着重要作用. GLS完好性是终端区进近着陆引导应用的重要参数,是可靠性的重要依据,然而目前普通用户只关注导航定位的精度而没有考虑定位结果的可靠性,航空导航领域的机载对定位结果的可靠性要求极高,因此针对完好性故障监测性能展开研究分析,提出了一种接收机钟差调整策略并对其有效性进行仿真验证,并验证了完好性故障排除及未排除两种情况对定位精度及完好性的影响,进而证明完好性故障监测可保障GLS的系统性能、运行能力和安全性能达到预期要求. 相似文献
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Prediction and analysis of GBAS integrity monitoring is important, especially at the airports where a GBAS station it to be installed. Based on existing standard documents and published research, we present a software tool for GBAS availability prediction. Simulations have been conducted that include single point, single approach path, and multiple repetitions of a same approach path in order to analyze the availability of GNSS signal integrity monitoring with a GBAS at LinZhi airport. The results show that the long-term 24-h service availability figure at two typical single points along the approach path for GBAS Approach Service Type C (GAST C) is above 99.999 % for each point, and for GBAS Approach Service Type D (GAST D) at three typical single points, it is lower than 99.8 % for each point. The unavailability percentage over a 24-h period is 0.76 and 2.40 % for GAST C and GAST D, respectively. The results of sensitivity tests show that the impact of the mask angle and the latitude on the GBAS availability at LinZhi airport are more important than that of the constellation. Our conclusions could also be of interest for the implementation of GBAS stations at other plateau airports. 相似文献
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In this paper, we present the development of a local area differential GPS testbed of the ground-based augmentation system (GBAS) as the future airport navigation facility in the Taipei Flight Information Region (FIR) in Taiwan. The testbed is mainly a GBAS ground facility, which consists of a ground station, three GBAS receivers, and a VDL (VHF data link) broadcast antenna. We also present an airborne GPS/GBAS prototype receiver in this paper. The airborne subsystem (a GPS/GBAS receiver) receives the correction messages from the ground subsystem to perform a differential GPS (DGPS) positioning. In order to provide an ILS-look-alike approach and landing, the output messages of the airborne receiver are packed in an ARINC 429 format. The proposed airborne system has a software-based global navigation satellite system (GNSS) receiver structure. 相似文献
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根据机场实施精密导航技术（RNP）的要求,国际民航组织（ICAO）提出地基增强系统（GBAS）,GBAS必将成为未来发展的必然趋势。但是在复杂的机场环境下,卫星信号易受外界影响和干扰,连续性不足,进而影响GBAS系统完好性性能的实施。因此,本文提出了伪卫星与北斗卫星联合定位增强GBAS的方法,并从加入伪卫星后的精度因子（DOP）、多参考一致性检测（MRCC）、完好性等方面进行了对比仿真分析。仿真结果表明,增加伪卫星后的系统精度因子得到了明显改善（PDOP小于3）,同时提高了完好性性能,能够为复杂环境下的机场提供GBAS CAT Ⅱ类及以上等级的精密进近服务。 相似文献
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针对大型无人机与民用客机在同一空域环境中运行,使用传统的单点定位方法,定位精度低,可靠性差,不能满足大型无人机进近着陆需求的问题,提出了一种提高大型无人机进近着陆过程中的定位精度的方法。利用陆基增强系统,为传统的伪距观测提供差分修正,使大型无人机在进近着陆过程中获得更精确的高程信息。实验结果表明,相比于传统的单点定位方法,利用陆基增强系统进行无人机进近下降着陆,在很大程度上提高了无人机的高程定位精度,确保了无人机在进近着陆过程中的运行安全。研究结果为无人机与民用客机的联合运行以及未来"空管一体化"标准的制定提供了重要理论支撑。 相似文献
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We address the differences in the ways the Instrument Landing System (ILS) and Ground-Based Augmentation System (GBAS) offer approach guidance, and their principles and methods. We perform comparative analysis of the accuracy of deviation between the GBAS Landing System (GLS) and ILS by means of flight tests, using the flight inspection aircraft at Gimpo International Airport. Our results show that the ILS deviation error increases as the distance between the threshold of runway and the aircraft increases; on the other hand, the GLS deviation error is stable, within the range of ±0.5 to ±2 m lateral and vertical deviation, respectively. We also analyze the alignment accuracy of the ILS and GLS based on the evaluation criteria of Category I of the Federal Aviation Administration, and our analysis results confirm that both systems satisfy the requirements (lateral: ±0.1°, vertical: ±0.05°). 相似文献
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针对民航飞机利用陆基增强系统(GBAS)进行精密进近着陆过程中,GBAS机载甚高频数据广播(VDB)接收机所受到的同频干扰问题,提出采用盲信号分离算法,对VDB接收机所接收到的期望信号与同频干扰信号进行分离,并通过识别解码数据中的机场标识(ID),得到所需期望信号,从而抑制同频干扰信号. 分析并仿真了基于快速固定点(Fast ICA)算法、自然梯度算法和等变自适应分离(EASI)算法,对VDB接收机接收到的混合信号进行分离的机理和同频干扰抑制的实现. 仿真结果表明,这三种算法均能有效分离期望信号与同频干扰信号,进而进行同频干扰抑制,并通过比较三种算法的收敛速度、串音误差和误码率,得出 Fast ICA算法更适合用于VDB信号的同频干扰抑制. 相似文献
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A global navigation satellite system augmentation system availability analysis tool has been developed to simulate a ground-based augmentation system (GBAS) prototype, an integrity monitor test bed, to evaluate its operational benefits at an airport of interest. The proposed availability simulation tool includes all GBAS ground facility algorithms as well as a graphical user interface that allows the user to modify simulation options and parameters. The output of the simulation tool is presented in a Stanford chart to help visualize the performance. The chart indicates the availability and integrity. The performance is evaluated primarily in the vertical position domain because of the weaker satellite geometry and more stringent required navigation performance as compared to those of the horizontal position domain. The simulation tool is implemented in Qt (http://www.qt.io/), an open-source cross-platform toolkit, allowing the tool to run on various devices. The computations are performed in the associated C++ code. The Newark Liberty International Airport (ICAO code: KEWR) is used as a simulation example to demonstrate the utility of the developed tool for investigating how reduced error models impact GBAS availability at the airport. 相似文献
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Ionospheric disturbances present a considerable hazard to single-frequency satellite navigation systems for airborne users. We discuss our implementation of three ionospheric threat models in the DLR “multi-output advanced signal test environment for receivers” global navigation satellite system simulator, which is based on Spirent GSS 7780/7790 signal generator. These threat models include the standard front-based threat model developed for the integrity assessment of ground-based augmentation systems (GBAS), a simplified plasma bubble model, and ionospheric scintillation, which can be combined with either of the two previously mentioned models. These effects can now straightforwardly be simulated at the German Aerospace Center’s research facilities. As an example, we simulate a GBAS ground facility with code–carrier divergence monitoring, affected by an ionospheric front, and we show the results of a simulation with coincidental occurrence of a plasma bubble and scintillation with an S 4 index of 0.4. 相似文献
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One of the key approaches to monitor the integrity of Global Satellite Navigation Systems (GNSS) is receiver autonomous integrity monitoring (RAIM). Existing RAIM algorithms utilise two tests in the position domain (for RAIM availability) and measurement domain (for failure detection). This paper proposes an alternative RAIM algorithm, which is based entirely in the measurement domain. This algorithm can be used for sensitivity analyses to support performance specification and system design. It can also be used during actual flight operations where the trigger is the phase of flight and its required navigation performance (RNP) parameters. This is made possible by computationally efficient calculation of the chi-squared parameters. The algorithm reverts to the current approach if the phase of flight is unknown. Simulation results for non-precision approach (NPA) have been used to demonstrate the effectiveness of the proposed algorithm. 相似文献
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A major challenge in using GPS guidance for aircraft final approach and landing is to reject interference that can jam reception
of the GPS signals. Antenna arrays, which use space–time adaptive processing (STAP), significantly improve the signal to interference
plus noise ratio, but at the possible expense of distorting the received signals, leading to timing biases that may degrade
navigation performance. Rather than a sophisticated calibration approach to remove biases introduced by STAP, this paper demonstrates
that a relatively compact calibration strategy can substantially reduce navigation biases, even under elevated interference
conditions. Consequently, this paper develops an antenna bias calibration strategy for two classes of adaptive array algorithm
and validates this method using both simulated and experimental data with operational hardware in the loop. A proof-of-concept
system and an operational prototype are described, which implement the adaptive antenna algorithms and deterministic corrections.
This investigation demonstrates that systems with adaptive antenna arrays can approach the accuracy and integrity requirements
for automatic aircraft landing, and in particular for sea-based landing on board aircraft carriers, while simultaneously providing
significant attenuation of interference. Evidence suggests that achieving these goals is possible with minimal restrictions
on system hardware configuration—specifically, limitations on the permissible level of antenna anisotropy and the use of sufficient
analog-to-digital converter resolution. 相似文献
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为获取民航客机落地前的高精度位置,本文探讨了一种基于多传感器的民航客机高精度定位方法。在飞机飞行过程中,机载数据记录器会记录整个飞行过程中GPS接收机、无线电高度表、惯性导航系统等传感器数据;在飞机落地后,利用无线电高度表数据、GPS数据进行位置差分,再利用惯性导航数据进一步优化,可大幅提高落地前垂直定位精度。结果表明,通过本文方法在机场跑道入口前2 km,飞机定位精度大幅提高,垂直定位精度可以达米级,满足事后调查需求。 相似文献
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Satellite-Based Augmentation Systems (SBASs) enhance the global navigation satellite system (GNSS) to support all phases of flight by providing required accuracy, integrity, continuity, and availability. The Korean SBAS program was recently initiated to develop a single-frequency SBAS aiming to provide Approach Procedure with Vertical guidance (APV)-I Safety-of-Life (SoL) service to aviation users by 2022 within the Korean region. We assess the preliminary availability of the single-frequency SBAS which will be deployed in the Korean peninsula. The resulting system performance shall be used as a baseline to design system components and specifications. The fundamental components of SBAS architecture, SBAS monitor network, geostationary earth orbiting satellite parameters, and ionospheric grid point mask, are defined and their effects on system performance are investigated. Ionospheric correction and integrity algorithm parameters including an ionospheric irregularity threat model are determined using data collected from the Korean GNSS network. The coverage of 99.9 % availability for APV-I service increases from approximately 70 % for the baseline case to 100 % when SBAS monitor stations are expanded to overseas. Even with the expanded monitor network, however, 90 % and less than 95 % availability for LPV-200 service can be achieved only in a very limited region. 相似文献
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Jörg F. Wagner 《GPS Solutions》2005,9(3):179-193
During the last years, the International Symposia on Precision Approach and Automatic Landing (ISPA) have shown a considerable change in the significance of integrated landing systems. At the first ISPA conference in 1995, the combination of inertial sensors and GNSS receivers was thoroughly discussed and appeared to be a very promising concept, especially with respect to ‘Integrity’ and ‘Continuity’. Ever since, this particular combination of sensors has received little attention. A comprehensive discussion of the technical background of this setback for integrated landing systems did not take place, primarily because of the popular opinion that the Kalman filter algorithm, which is the system integration kernel, is not sufficiently stable. The true reason has meanwhile been identified. The aiding of an inertial navigation system by only one GNSS antenna is insufficient in phases of low aircraft dynamics such as in the case of final approach. Instead, a multi-antenna system is required with antennas widely distributed over the aircraft structure. This latter approach, however, causes problems due to structural flexibilities. To show that an integrated system based on inertial sensors and widely distributed GNSS antennas is technically feasible, the paper discusses the following topics. (1) Unstable system performance during final approach for 1-antenna-aiding. (2) Improving the system performance prior to using additional antennas. (3) Effect of the antenna distribution. (4) Integrated systems for distributed sensors and flexible aircraft structures. The paper shows that integrated systems are still an attractive candidate for automatic landing equipment preserving the advantages with respect to ‘Integrity’ and ‘Continuity’. 相似文献
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Dong-Hwan Hwang Sang Heon Oh Sang Jeong Lee Chansik Park Chris Rizos 《GPS Solutions》2005,9(4):294-311
Due to their complementary features of GPS and INS, the GPS/INS integrated navigation system is increasingly being used for
a variety of commercial and military applications. An attitude determination GPS (ADGPS) receiver, with multiple antennas,
can be more effectively integrated with a low-cost IMU since the receiver gives not only position and velocity data but also
attitude data. This paper proposes a low-cost attitude determination GPS/INS integrated navigation system. The proposed navigation
system comprises an ADGPS receiver, a navigation computer unit (NCU), and a low-cost commercial MEMS IMU. The navigation software
includes a fault detection and isolation (FDI) algorithm for integrity. In order to evaluate the performance of the proposed
navigation system, two flight tests have been performed using a small aircraft. The first flight test confirmed the fundamental
operation of the proposed navigation system and the effectiveness of the FDI algorithm. The second flight test evaluated the
performance of the proposed navigation system and demonstrated the benefit of GPS attitude information in a high dynamic environment.
The flight test results show that the proposed ADGPS/INS integrated navigation unit gives reliable navigation performance
even when anomalous GPS data is provided and gives better navigation performance than a conventional GPS/INS unit. 相似文献
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陆基增强系统(GBAS)是利用载波相位平滑伪距差分修正实现对导航辅助定位的. 其中,平滑时间常数是影响载波相位平滑伪距精度的关键参数. 本文分析研究了不同平滑时间下电离层时间梯度和空间梯度对Hatch滤波的影响. 在结合电离层时空梯度和多径效应引起的滤波总误差方差的基础上,推导出自适应的最优平滑时间常数. 分别对GBAS静态和动态两种环境下的定位误差进行实验,实验结果表明,采用本文推导出的自适应平滑时间常数降低了GBAS伪距测量误差,从而使定位精度得到增强. 相似文献
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本文为低空无人机平台弱控制航摄影像建立符合航测处理要求的区域网,提出了基于无人机飞控数据的无人机影像航带整理技术;分析了无人机影像航测处理区域网构建要求,提出针对无人机航测处理的航带整理技术流程;设计了基于飞控姿态数据的无人机起降和转弯影像自动剔除算法,自动生成航带;并提出了基于飞控数据快速计算像片FOV算法,构建区域网内像对链接关系;对实际无人机航摄的两个测区进行航带整理实验,结果表明基于飞控数据可快速构建区域网,满足空三匹配和挑片测图要求。 相似文献