A5075617613- GNSS positioning and interference
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Inertial Sensor and Navigation
- Air Traffic Management and Optimization
- Railway Engineering and Dynamics
- Wireless Communication Networks Research
- UAV Applications and Optimization
- Astronomical Observations and Instrumentation
- Satellite Communication Systems
- Railway Systems and Energy Efficiency
- Indoor and Outdoor Localization Technologies
- Electrical Contact Performance and Analysis
- Vehicular Ad Hoc Networks (VANETs)
- Aerospace and Aviation Technology
- Autonomous Vehicle Technology and Safety
- Parallel Computing and Optimization Techniques
- Atmospheric and Environmental Gas Dynamics
- Earthquake Detection and Analysis
- Transportation Systems and Safety
- Astro and Planetary Science
- Robotic Path Planning Algorithms
- Distributed and Parallel Computing Systems
- Mobile Agent-Based Network Management
- Advanced Data Compression Techniques
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2016-2024
Karlsruhe Institute of Technology
2016-2023
European Space Research and Technology Centre
2022
ZHAW Zurich University of Applied Sciences
2022
Institute of Navigation
2019-2021
Roma Tre University
2020
Universidad de Oviedo
2017
This paper presents the performance analysis of signals from Galileo satellites in E1 and E5a frequency bands GPS L5 as measured by DLR's experimental ground-based augmentation system. The results show that raw noise multipath level are smaller than L1. new also less sensitive to choice carrier-smoothing time constant. Furthermore, inter-frequency biases affect dual-frequency processing investigated. These differ between depend on satellite receiver hardware, but they can be determined a...
Ground transportation systems demand accurate and robust localization functions. Satellite navigation is considered a key element in those systems, but its position determination can be highly corrupted urban environments because of the presence reflected signals (i.e. multipath). This paper deals with detection multipath code measurements GNSS receivers for mobile users scenarios. First, we discuss different alternatives limitations to properly isolate autonomously at receiver based on...
In the next generation of Ground Based Augmentation System (GBAS) corrections and integrity parameters for two frequencies multiple constellations will be provided. However, capacity VDB (VHF Data Broadcast) link providing those to users is strongly limited. Thus all new would either require a longer update rate or limitation on number satellites which are this paper we propose satellite selection method allows fast variable sized, quasi-optimal subset visible GNSS satellites. The proposed...
The ground-based augmentation system (GBAS) is the cornerstone for enabling automated landings without instrument landing (ILS). Currently, GBAS evolving to approach service type-D (GAST-D) category III landings. This development toward GAST-D extends via use of multiple frequencies (L1/L2 and L5) global navigation satellite constellations. requires correction data be broadcast aircraft, which currently handled VHF (VDB) datalink. However, VDB has several known shortcomings: 1) low...
View Video Presentation: https://doi.org/10.2514/6.2021-3199.vid HorizonUAM is a DLR project to research the vision of urban air mobility. One important topic safety and security aspect. This paper discusses considerations in areas of: safe autonomy, reliable multisensor navigation, robust efficient communication, U-space traffic, finally cyber-physical security. As basis for future discussion, challenges gaps are identified, furthermore context briefly outlined. From perspective, missing...
The project City-ATM, launched by the German Aerospace Center DLR in 2018, aims to integrate new airspace users, such as unmanned aerial vehicles, into uncontrolled airspace. An air traffic management and flow control concept were developed. phase 1 demonstration 2019 showed a bridge inspection featuring, amongst other elements, flight of several drones limited area, beyond visual line sight operation, strategic planning considering geo-fences, tactical conflict detection. To enrich base...
In this paper, we evaluate the performance of dual-frequency airborne ionospheric gradient monitor proposed for multi-constellation (DFMC) Ground Based Augmentation Systems (GBAS) at different distances from airport. We use two types thresholds assessment: (i) a constant threshold derived operational requirements, and (ii) dynamic that increases with distance Increasing allows more error within position solution, but also enables primary single-frequency modes without need to switch...
In this work an overview of numerous possible processing modes in future dual frequency, constellation GBAS is given and compared to the current GAST D standard. We discuss individual error contributions protection levels give general processing. Based on consequences when adding a second as well frequency are investigated. Geometrical implications changes residual differential bounds studied separately first. terms geometry comparison between single case presented using dilution precision...
Abstract Communication, Navigation and Surveillance (CNS) technologies are key enablers for future safe operation of drones in urban environments. However, the design navigation these new applications is more challenging compared to e.g., civil aviation. On one hand, use cases operations environments expected have stringent requirements terms accuracy, integrity, continuity availability. other airborne sensors may not be based on high-quality equipment as aviation solutions need rely tighter...
Currently proposed airborne multipath models are based on 100-second time-invariant (for single-frequency L1/E1 and L5/E5a signals) time-variant the ionospheric-free combination of these smoothing to describe behavior aiborne error in different applications (e.g. Satellite Based Augmentation Systems Advance Receiver Autonomous Integrity Monitoring). However, recently architecture for dual-frequency multi-constellation (DFMC) GroundBased (GBAS) incorporates characteristics, as use...
With the new upcoming GNSS constellation in future it might no longer be possible to use all satellites view for navigation due limited tracking channels. This is particular true context of Advanced Receiver Autonomous Integrity Monitoring (ARAIM), where dual frequency favorable mitigate ionospheric disturbances. To address issues channels we propose two different selection strategies adapted Horizontal ARAIM this paper. First a bare geometric approach which comes with almost additional...
<h3>Abstract</h3> Large ionospheric gradients acting between a Ground Based Augmentation System (GBAS) reference station and an aircraft on approach could lead to hazardous position errors if undetected. Current GBAS stations provide solutions against this threat that rely the use of “worst-case” conservative models, which limit availability system. This paper presents methodology capable detecting in real time estimating actual model parameters based network dual-frequency...
In this paper we present the expected performance of different processing modes for a future dual-constellation dual-frequency Ground Based Augmentation System (GBAS). The evaluations are based on measurements collected during flight trials. We discuss changes to residual differential error each mode. our previous work derived preliminary airborne multipath (sigma_air ) and ground (sigma_gnd curves Galileo E1 E5a signals GPS L5 signals. use these models in evaluations. After discussing...
Certified Ground Based Augmentation Systems (GBAS) as of today operate using only GPS signals in the L1 frequency band to enable precision approach guidance for landing aircraft. Ionospheric activity (i.e., scintillations and/or large abnormal ionospheric gradients) is a major limitation availability current GBAS services, especially equatorial and polar regions. To overcome these limitations, developments aim at extending use dual-frequency multi-constellation (DFMC) techniques. Using on...
When incorporating multiple constellations into future ground based augmentation systems (GBAS), a problem with limited VDB (VHF data broadcast) capacity might arise. Furthermore, the number of airborne receiver tracking channels could be insufficient to use all visible satellites. One way cope these issues is perform satellite selection limit used satellites minor impact on performance. This paper investigates different factors that constrain approach simply selecting "the best set in every...
Satellite navigation plays a critical role in new railway signaling and train control systems. It will allow higher levels of automation at reduce cost installation maintenance as compared to current infrastructure-based technologies. However, order be integrated systems, GNSS must guarantee the stringent safety requirements. has been extensively quantified for aviation community, however, environment probability local hazards like interferences is larger due its operation non-restricted...
The VHF Data Broadcast (VDB) data link is responsible for transmitting Ground Based Augmentation System (GBAS) corrections from the GBAS ground station to aircraft. Thus, it a major bottleneck evolution and security of GBAS. It provides limited bandwidth, range, only line-of-sight capabilities, no cyber-security protections transmitted data. Overcoming these constraints required future calls an alternative A promising candidate L-band Digital Aeronautical Communications (LDACS). First...
In this paper we present a modular framework to classify railway track areas regarding the expected presence of local GNSS threats. This information might be critical for safe signalling operation, example determine where virtual balises could placed safely. We show first how different threats can detected using dedicated detection algorithms and these individual results then transformed from time domain. An overall decision logic is subsequently used identify an area as suitable or...
In this paper we analyze and discuss the impact of ionospheric scintillations multipath on availability current single-frequency single-constellation Ground Based Augmentation System (GBAS). Scintillation effects, which usually occur around plasma bubbles, cause receiver to lose lock one or more satellites, leading potentially unfavorable satellite geometries for an airborne user. We simulate different bubble dimensions distinct locations in sky order illustrate that use a second...
Ionospheric anomalies, like ionospheric gradients, might produce a difference between the error experienced by Ground Based Augmentation System (GBAS) reference station and aircraft on approach. This delay could lead to position errors if undetected. For that reason, GBAS Approach Service Types (GAST) C D provide solutions against this threat, but methods employed still face challenges. In case of GAST C, integrity parameters are inflated in order exclude potentially usable satellite...
This paper proposes a method for monitoring the difference in ionosphere between GBAS ground station and an airborne user from single frequency L1/E1 corrections L5/E5a corrections. The absolute ionospheric delay at cannot be estimated only. Therefore, monitored test statistic is of estimate system similar pseudo-ionospheric estimation station. In order to make two estimates comparable common part has removed. affected by noise multipath measurements Based on airworthiness performance...
The future architecture for Dual-Frequency Multi-Constellation Ground-Based Augmentation Systems (DFMC GBAS), known as GBAS Approach Service Type (GAST) E, is designed to rely on measurements from two frequency bands, specifically L1/E1 and L5/E5a. However, unintentional Radio Frequency Interference (RFI) could affect one of the frequencies, typically L1/E1, potentially leaving with just a single operating frequency. In such scenario, GAST E cannot function intended, necessitating definition...
Ionospheric anomalies, like large ionospheric gradients, might produce a difference between the error experienced by Ground Based Augmentation System (GBAS) reference station and aircraft on approach. This delay could lead to hazardous position errors if undetected. For that reason, GBAS Approach Service Types (GAST) C D provide solutions against this threat, but methods employed still face challenges limiting availability in certain cases, especially regions with severe conditions. issue is...
In this paper we describe a method to monitor for difference in the ionospheric delay observed by ground station of Ground Based Augmentation System (GBAS) and an airborne user. case detection affected satellite can be excluded or switch free processing mode triggered. As it is not possible estimate absolute at from transmitted corrections directly, compare pseudo-ionospheric with after removing biases. We then show performance proposed monitoring architecture flight trials our GBAS test...