Required navigation performance

About: Required navigation performance is a research topic. Over the lifetime, 343 publications have been published within this topic receiving 3477 citations. The topic is also known as: RNP.

Integrated Positioning Algorithms for Transport Telematics Applications

Abstract: A range of transport telematics applications and services require continuous and accurate positioning information of the vehicles traveling on the road network. Two types of information are essential for such telematics applications and services. These are the determination of the vehicle position and the determination of the physical location of the vehicle on the road network. The most common devices used for vehicle positioning are based on GPS, Dead-Reckoning (DR) sensors, Map Matching (MM) and microwave beacons. The use of these devices either in isolation or combination depends on the Required Navigation Performance (RNP) parameter specifications (accuracy, integrity, continuity and availability). Furthermore, the capability to identify the physical location of a vehicle is a key requirement in transport telematics applications. In order to achieve the RNP, system and sensor complementarity, such as in the case of the integration of GPS, DR and digital map data could be used to enhance geometric positioning capability. MM not only enables the physical location of the vehicle to be identified but also improves the positioning capability if a good digital map is available. A key factor in the integration of different devices is the knowledge of the various failure modes (including error sources). This paper develops two integrated positioning algorithms for transport telematics applications and services. The first is an Extended Kalman Filter (EKF) algorithm for the integration of GPS and low cost DR sensors to provide continuous positioning in built-up areas. The second takes this further by integrating the GPS/DR output with map data in a novel a map-matching process to both identify the physical location of a vehicle on the road network and improve positioning capability. The proposed MM algorithm is validated using a higher accuracy reference (truth) of the vehicle trajectory as determined by high precision positioning achieved by the carrier phase observable from GPS. The results demonstrate a 90% coverage in a typical built-up environment over a 4-hour duration for a stand-alone GPS employing a single frequency high sensitivity receiver/antenna assembly. The integrated GPS/DR approach employing the EKF gives 100% coverage at an accuracy level better than 30m (2o). The MM validation results show that 100% link identification is achieved with the proposed MM algorithm, with a maximum horizontal positioning error of 6m. The results also demonstrate the importance of the quality of the digital map data to the map matching process.

Fuel burn and emissions evaluation for a missed approach procedure performed by a B737-400

Abstract: This paper presents the results of a study conducted at the Laboratoire de recherche en commande active, avionique et aeroservoelasticite, Ecole de technologie superieure, regarding the costs in fuel burn and pollutant emissions corresponding to a flight profile determined by a missed approach procedure. The evaluated missed approach flight profile starts at the point where the missed approach decision is made and ends at the same point, after the aircraft completes the missed approach procedure. This study uses the fuel burn and pollutant emissions data for a Boeing 737-400 aircraft (chosen at random for this study), published by the European Environment Agency, and the standard flying cycle model elaborated by Group 08 of the Task Force on Emissions Inventories and Projections a task force created by the United Nations Economic Commission for Europe (UN ECE) / the co-operative program for the monitoring and evaluation of the long-range transmission of air pollutants in the Europe (EMEP). The missed approach flight profile is based on the Area Navigation/Required Navigation Performance procedure for runway 13R of the King County International Airport/Boeing Field (BFI) in Seattle. Four study cases are considered for the missed approach flight evaluation. These cases correspond to four navigation profiles – a combination of two lateral navigation profiles, one with a 20 nautical miles holding pattern and the other without, and two vertical navigation profiles. The results obtained for the missed approach flight profiles, in terms of fuel burn and emissions, are compared with the fuel burn and emissions reference data corresponding to a standard approach procedure and complete flights (from taxi out to taxi in).

An innovative navigation and guidance system for small unmanned aircraft using low-cost sensors

Abstract: Purpose – The purpose of this paper is to design a compact, light and relatively inexpensive navigation and guidance system capable of providing the required navigation performance (RNP) in all phases of flight of small unmanned aircrafts (UA), with a special focus on precision approach and landing. Design/methodology/approach – Two multi-sensor architectures for navigation and guidance of small UA are proposed and compared in this paper. These architectures are based, respectively, on a standard extended Kalman filter (EKF) approach and a more advanced unscented Kalman filter (UKF) approach for data fusion of global navigation satellite systems (GNSS), micro-electro-mechanical system (MEMS)-based inertial measurement unit (IMU) and vision-based navigation (VBN) sensors. Findings – The EKF-based VBN-IMU-GNSS-aircraft dynamics model (ADM) (VIGA) system and the UKF-based system (VIGA+) performances are compared in a small UA integration scheme (i.e. AEROSONDE UA platform) exploring a representative cross-se...

Integrity monitoring for precision approach using kinematic gps and a ground-based pseudolite

Abstract: Although DGPS is inherently robust to space-vehicle-related ranging errors, failures in the differential station or airborne receiver can be a threat to continuous precise positioning. The stringent required navigation performance (RNP) for Category III precision landing, therefore, establishes the need for an active integrity verification system. Carrier tracking of ground-based pseudolites can provide comprehensive integrity. The large geometry change that occurs during overflight of a ground-based pseudolite and the great precision of carrier-phase measurements can provide the leverage for effective autonomous integrity monitoring. The measurement residual statistic can be used to detect a wide range of conceivable fault scenarios occurring during the pseudolite overflight, including cycle slips, intentional tampering, and airborne database errors. The potential for autonomous integrity verification for Category III approach is demonstrated through analysis, simulation, and flight tests performed in a single-engine aircraft.

Navigation and Guidance System Architectures for Small Unmanned Aircraft Applications

Abstract: Two multisensor system architectures for navigation and guidance of small Unmanned Aircraft (UA) are presented and compared. The main objective of our research is to design a compact, light and relatively inexpensive system capable of providing the required navigation performance in all phases of flight of small UA, with a special focus on precision approach and landing, where Vision Based Navigation (VBN) techniques can be fully exploited in a multisensor integrated architecture. Various existing techniques for VBN are compared and the Appearance-Based Navigation (ABN) approach is selected for implementation. Feature extraction and optical flow techniques are employed to estimate flight parameters such as roll angle, pitch angle, deviation from the runway centreline and body rates.