1,720,995 research outputs found
Supplemental dataset for "Weather field reconstruction using aircraft surveillance data and a novel meteo-particle model"
No full text<p>This dataset contains the source data used for the experiments of the paper titled "Weather field reconstruction using aircraft surveillance data and a novel meteo-particle model".</p>Content and structure of the dataset can be found in README documen
OpenAP.top: Open Flight Trajectory Optimization for Air Transport and Sustainability Research
No full textTrajectory optimization has been an active area of research for air transport studies for several decades. But almost all flight optimizers proposed in the literature remain close-sourced, which presents a major disadvantage for the advancement of scientific research. This optimization depends on aircraft performance models, emission models, and operational constraints. In this paper, I present a fully open trajectory optimizer, OpenAP.top, which offers researchers easy access to the complex but efficient non-linear optimal control approach. Full flights can be generated without specifying flight phases, and specific flight segments can also be independently created. The optimizer adapts to meteorological conditions and includes conventional fuel and cost index objectives. Based on global warming and temperature potentials, its climate objectives form the basis for climate optimal air transport studies. The optimizer’s performance and uncertainties under different factors like varying mass, cost index, and wind conditions are analyzed. Overall, this new optimizer brings a high performance for optimal trajectory generations by providing four-dimensional and wind-enabled full-phase optimal trajectories in a few seconds. View Full-TextControl & Simulatio
WRAP: An open-source kinematic aircraft performance model
No full textOpen access to flight data from Automatic Dependent Surveillance-Broadcast (ADS-B) has provided researchers with more insights for air traffic management than aircraft tracking alone. With large quantities of trajectory data collected from a wide range of different aircraft types, it is possible to extract accurate aircraft performance parameters. In this paper, a set of more than thirty parameters from seven distinct flight phases are extracted for common commercial aircraft types. It uses various data mining methods, as well as a maximum likelihood estimation approach to generate parametric models for these performance parameters. All parametric models combined can be used to describe a complete flight that includes takeoff, initial climb, climb, cruise, descent, final approach, and landing. Both analytical results and summaries are shown. When available, optimal parameters from these models are also compared with the Base of Aircraft Data and the Eurocontrol aircraft performance database. This research presents a comprehensive set of methods for extracting different aircraft performance parameters. It also provides the first set of open parametric performance data for common aircraft types. All model data are published as open data under a flexible open-source license.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Control & Simulatio
The 1090 Megahertz riddle: A guide to decoding mode S and ADS-B signals: Second edition
No full textInteractive Textbook. In the last twenty years, aircraft surveillance has moved from controller-based interrogation to automatic broadcast. The Automatic Dependent Surveillance-Broadcast (ADS-B) is one of the most common methods for aircraft to report their state information like identity, position, and speed. Like other Mode S communications, ADS-B makes use of the 1090 megahertz transponder to transmit data. The protocol for ADS-B is open, and low-cost receivers can easily be used to intercept its signals. Many recent air transportation studies have benefited from this open data source. However, the current literature does not offer a systematic exploration of Mode S and ADS-B data, nor does it explain the decoding process.This book tackles this missing area in the literature. It offers researchers, engineers, and enthusiasts a clear guide to understanding and making use of open ADS-B and Mode S data. The first part of this book presents the knowledge required to get started with decoding these signals. It includes background information on primary radar, secondary radar, Mode A/C, Mode S, and ADS-B, as well as the hardware and software setups necessary to gather radio signals. After that, the 17 core chapters of the book investigate the details of all types of ADS-B signals and commonly used Mode S signals. Throughout these chapters, examples and sample Python code are used extensively to explain and demonstrate the decoding process. Finally, the last chapter of the book offers a summary and a brief overview of research topics that go beyond the decoding of these signals.Control & Simulatio
Aircraft Drag Polar Estimation Based on a Stochastic Hierarchical Model
No full textThe aerodynamic properties of an aircraft determine a crucial part of the aircraft performance model. Deriving accurate aerodynamic coefficients requires detailed knowledge of the aircraft’s design. These designs and parameters are well protected by aircraft manufacturers. They rarely can be used in public research. Very detailed aerodynamic models are often not necessary in air traffic management related research, as they often use a simplified point-mass aircraft performance model. In these studies, a simple quadratic relation often assumed to compute the drag of an aircraft based on the required lift. This so-called drag polar describes an approximation of the drag coefficient based on the total lift coefficient. The two key parameters in the drag polar are the zero-lift drag coefficient and the factor to calculate the lift-induced part of the drag coefficient. Thanks to this simplification of the flight model together with accurate flight data, we are able to estimate these aerodynamic parameters based on flight data. In this paper, we estimate the drag polar based on a novel stochastic total energy model using Bayesian computing and Markov chain Monte Carlo sampling. The method is based on the stochastic hierarchical modeling approach. With sufficiently accurate flight data and some basic knowledge of aircraft and their engines, the drag polar can be estimated. We also analyze the results and compare them to the commonly used Base of Aircraft Data model. The mean absolute difference among 20 common aircraft for zero-lift drag coefficient and lift-induced drag factor are 0.005 and 0.003 respectively. At the end of this paper, the drag polar models in different flight phases for these common commercial aircraft types are shared.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Control & Simulatio
Feasibility and accuracy of Received Signal Strength-based Multilateration for aircraft localization using crowdsourced data
No full textTo verify the aircraft position provided by Automatic Dependent Surveillance-Broadcast (ADS-B)transponders, multilateration (MLAT) technique incorporates time difference of arrival (TDOA) measurements at multiple ground-based receivers to estimate the corresponding distances between those and the aircraft. This approach requires precise time synchronization among receivers that can not always be guaranteed. Alternatively, received signal strength (RSS) measurements can be utilized to derive these distances. In this paper, crowdsourced RSS measurements from 43 receivers were used to construct parameterized signal propagation models that capture the relationship between RSS and distance. The quality of these modelswas evaluated by examination of model parameter and estimated distance errors in both 2D and 3D. The results show that at most 26.3% of available RSS measurements could be represented by the models given the cut-off criteria for model parameter errors. Moreover, the models with higher parameter errors demonstrated poor ability to capture RSS measurements at greater distances. The localization errors in MLAT with TDOA were compared to MLAT with RSS where the later resulted in more accurate position estimation in cases where the receiver clocks were not synchronized. However, MLAT with TDOA generally produced significantly more accurate position estimation given the reliable timestamps of signal arrival. The assessment of localization accuracy using crowdsourced data resulted in root mean square errors of 118.1 meters in MLAT with TDOA and 9858.6 meters in MLAT with RSS in 2D, representing the best results obtained.Aerospace Engineerin
Streamlining multi-stop flights with ground transportation
No full textPassenger transportation in Europe is often duplicated using modes of transportation which are environmentally inefficient. Quantifying the carbon dioxide emission inefficiencies of flights versus transit is beneficial to understand the potential savings of a modal shift. In this paper, we analyze the emissions in Europe from multi-stop flights using flight data from March 2019. The excess emissions are quantified by comparing each multi-stop flight with an intermodal journey that does not exceed 60 minutes of extra travel time. We find that on average, transfer passengers using intermodality can reduce their journey’s total(segment) well-to-wheel and life-cycle assessment emissions by 33% (80%) and 30% (72%), respectively. 840 thousand (19 % of total) transfer passengers starting or ending their journey in Europe can skip the feeder flight while saving an average of 28 minutes of door-to-door travel time. For air travellers taking intra-European multi-stop flights, 157 thousand transfer passengers (10% of the total) do not have to even enter an airport. Further insights regarding the European mobility vision are made, with recommendations for various stakeholders.Aerospace Engineerin
Modeling and analyzing the environmental impact of short-to-medium range air and ground transports
No full textThe emissions of the transport sector inside the EU-27 have risen by 33 % between 1990 and 2019. A modal shift from unsustainable transport towards more environmentally friendly transport modes can be taken as one solution to mitigate the overall emission of the transport sector. In this paper, multiple open-source models and databases are utilized to compare travel emissions and time of air travel and various ground transport options, including car, bus, and rail. Compared with previous research that relies on closed-sourced or hand-collected data to extract public ground transportation routes information, this paper utilizes the openly accessible General Transit Feed Specification(GTFS) database, facilitating the calculation at a large scale inside EU-27. 820 pairs of routes between popular 41 city centers inside EU-27 are selected for comparison. The results consistently demonstrate that air travel always produces higher emissions per passenger than rail and bus travel for all routes. Emissions from cars are significantly influenced by occupancy rates and the type of vehicle fuel. The emissions from a single person in a petrol/diesel car can exceed those from air travel. However, if four people travel in a hybrid electric or electric vehicle, the per-passenger emission can be similar to rail. Among all public transport, the rail is the most competitive one to replace air travel by offering passengers similar travel time and reducing emissions. The trade-off factor between emissions and time is also investigated on its effect on the passenger route choice decision. In addition, this paper offers insights into the development of emission models and provides recommendations for various stakeholders.Aerospace Engineerin
Automatic Dependent Surveillance for Drones: a Design and Capacity Study
No full textThe consumer drone sector is expected to grow rapidly in the coming decades. In Europe alone, it is predicted that in excess of seven million such machines will be flying by 2050. This poses a risk of conflict in dense airspaces, with both aircraft and other drones. Such a growing market provides a need to make drones visible to ATC and other airspace users. While several passive surveillance methods exist, such as primary drone radar, a cooperative surveillance system would provide more data to airspace users and other drones to allow for features such as automatic separation. An Automatic Dependent Surveillance system concept is presented in this paper, allowing the drone to broadcast information about itself without external input. This is akin to ADS-B, from which the system inherits its format for the time being.The study's main contents are threefold. The first consists of recommendations made on the basis of literature. Then, a simulation approach to examine system capacity and related constraints through a sensitivity study is done. Finally, a hardware proof-of-concept, consisting of inexpensive and simple off-the-shelf components is built and tested. Overall, the paper demonstrates that such a system is indeed feasible. Through the literature, it was found that direct integration of the system with current ADS-B on the 1090 MHz frequency is possible, but may cause performance degradation for existing aircraft. Therefore, the carrier frequency and code allocation are changed. The simulation and capacity study shows that the system works in high-density scenarios (in excess of one drone per square kilometer), but will require additional work on hardware, format and modulation techniques to enable this. Finally, the hardware demonstrator shows that an inexpensive COTS implementation with a range of approximately 200 meters is possible, on hardware drawing less than five Watts of power.Aerospace Engineering | Control & Simulatio
Radio Frequency Fingerprinting for Aircraft Identification
No full textRadio frequency fingerprinting has been identified as a method to increase integrity in aircraft surveillance while retaining its openness. One way to uniquely determine transmitting devices is to distill the device its radio frequency (RF) fingerprint by looking at the physical features of the message signal it transmits. This physical layer fingerprint is the unique trace the transmitter leaves in the signals. This research proposes a method to RF fingerprint ADS-B and VDL2 messages to identify the transmitting aircraft using a complex-valued convolutional neural network model. Raw data from ADS-B and VDL2 messages are collected over multiple days using low-cost RTLSDR hardware. Results show that the model can identify ADS-B and VDL2 messages from up to 200 different aircraft based on the raw IQ preamble and bit synchronization samples of both signal protocols. Further analysis of the robustness of the model shows that the model accuracy can be highly affected by changing channel conditions during training and testing. This research shows that testing the RF fingerprinting model’s robustness to channel conditions is necessary since the models are prone to mistakenly considering channel information as transponder RF features.Aerospace Engineerin
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