In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, wide availability, and relative ease operability. Existing future applications UAVs include remote surveillance monitoring, relief operations, package delivery, communication backhaul infrastructure. Additionally, are envisioned as an important component 5G wireless technology beyond. The unique application scenarios necessitate...

A major modernization process in air traffic management for civil aviation is currently taking place under the framework of SESAR and NextGen Europe United States, respectively. Air required to meet needs sustainable growth Europe, worldwide are posing. key enabler this introduction improved communications, navigation, surveillance technologies. In article, new developments aeronautical communications presented, with special focus on air/ground technology L-band Digital Aeronautical...

The L-band digital aeronautical communications system (LDACS) is a key enabler of the new air traffic services and operational concepts necessary for modernization management (ATM). After its initial design, compatibility tests with legacy systems, functional demonstrations in laboratory, currently undergoing standardization process International Civil Aviation Organization (ICAO). However, LDACS has not been demonstrated flight yet. In this article, we present first in-flight demonstration...

In the paper, we present results from flight trials conducted to investigate characteristics of L-band air-to-ground radio channel for positioning applications. We discuss employed hardware setup, synchronization concept, calibration procedures, and investigated patterns. It is shown that setup suitable investigating both multipath structure absolute propagation time signals. The power delay Doppler profiles, as well time-of-arrival estimation accuracy, are presented.

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...

In the air-ground propagation channel, multipath severely affects performance of communication, navigation, and surveillance systems used in civil aviation. To gain a deeper understanding we are interested locations objects causing propagation. Therefore, this paper propose experimentally validate an algorithm to localize reflectors components based on channel sounding data collected using omnidirectional antennas. The relies superresolution parameter estimation tracking as well localization...

Non-stationary channel models play a crucial role in today's communication systems. Mobile-to-mobile channels are known to exhibit non-stationary behavior caused by the movement of transmitter and receiver. Non-stationarity can be addressed introducing time-variant stochastic functions such as instantaneous Doppler probability density function or characteristic function. An algebraic analysis (pdf) classical Cartesian coordinate system is only numerically tractable due trigonometric...

In the air-ground propagation channel, multipath severely affects performance of communication, navigation, and surveillance systems used in civil aviation. To verify aeronautical wireless transmission independently from expensive flight trials, a channel model for computer simulations is required. Based on an exhaustive measurement campaign, we propose geometry-based stochastic regional airport environment L-band. The proposed allows us to correctly reproduce non-stationarity impulse...

In order to cope with the increasing demand of communication capacity in aeronautical sector, Future Communications Infrastructure has been developed. For air ground communications currently two candidates are considered for L-band digital system. Both systems use frequency bands assigned both civil and military navigation systems. Hereby special interest is distance measurement equipment due its wide extensive aviation. Prior deployment any candidates, compatibility towards those legacy be...

The paper proposes a geometrical-statistical modeling approach for the air-ground channel communications, navigation, and surveillance (CNS) systems in L-band frequency range. We sketch architecture of model with its six elements show how their parameters can be derived from measurement data. Preliminary results obtained relatively small set data reveal that proposed is well suited to capture time variant behavior channel. However, considerably more extensive evaluation will necessary...

In this paper we discuss the first results from a set of flight experiments. The objective was to show that terrestrial ranging can support aviation services with sufficient accuracy for non-precision approach. experimental setup is based on using LDACS signals provide pseudorange measurements. data analysis reveals position solutions are compliant RNP 1 standards. We also propose feasibility 0.3 as ranging.

In order to cope with the increasing demand for communication capacity in aeronautical sector, Future Communications Infrastructure is currently being developed. For air-ground communications two candidates are considered as new L-band digital system. this paper, idea of using one these systems, namely LDACS1, navigation aid presented. Compared satellite based LDACS1 exhibits a significantly lower vulnerability intentional or unintentional interference. This due its larger received power....

• Proof of concept Excellent ranging performance with low complexity approach (Doppler smoothing)

The L-band Digital Aeronautical Communication System type 1 (LDACS1) has been recently proposed to provide an Alternative Positioning, Navigation, and Timing (APNT) service for aeronautics during possible GNSS (Global Navigation Satellite System) outages. To validate the use of LDACS1 communication signals as ranging sources in realistic scenarios, a flight measurement campaign performed. This paper presents discusses results obtained from data collected flight. Based on analysis measured...

We propose a method for describing the spatial correlation of ranging errors in terrestrial sources. The is based on characterizing terms azimuth and elevation angles, rather than three-dimensional space. change parameters makes simpler data collection setup, compared with full error model.

The presented work investigates a sparse Bayesian incremental automatic relevance determination (IARD) algorithm in the context of multipath parameter estimation super-resolution regime. corresponding problem is highly nonlinear and, general, requires an number components. In IARD approach individual components are processed sequentially, which permits tractable convergence analysis inference expressions. This leads to simple condition, termed here pruning that determines if component...

In this paper we discuss the feasibility of prototyping radionavigation hardware, designed to operate in ARNS band, by flight testing it 902-928 MHz ISM band. A central challenge effort was shared nature which causes high in-band interference levels and, consequently, a reduction signal-to-noise ratio. We propose mitigating strategies that enable operation as well methodology for assessing equivalence results with band measurements.

Today's voice-based air-ground communication system for aircraft guidance is suffering from increasing saturation of the VHF band in high density areas. Therefore European Union strives a transition analog voice to more spectrum efficient digital communication. This shall be realized, among others, through development and implementation L-band Digital Aeronautical Communications System (LDACS). In order verify suitability LDACS both communications navigation, flight trial campaign will...

Operating remotely piloted aircraft is not imaginable without a continuous data exchange between the air vehicle and remote pilot. This requires reliable links. One approach for such link discussed in community terrestrial system deployed C-band. A good knowledge of physical conditions communication channel, this case air-ground/ground-air indispensable development wireless Therefore we carried out 50 MHz bandwidth channel sounding campaign with transmitter an airborne receiver. In paper...