GNSS augmentation

About: GNSS augmentation is a research topic. Over the lifetime, 2478 publications have been published within this topic receiving 28513 citations. The topic is also known as: SBAS & Satellite Based Augmentation System.

3D-Precision Curved Approaches: A Cockpit View on ATM

Abstract: Pre-defined curved approach procedures represent an essential for noise abatement and may reduce the risk of controlled flight into terrain (CFIT) for today’s aviation considerably. In addition, a Ground Based Augmentation System (GBAS) supports accuracy and precision of the desired flight path. While the lateral guidance during current curved approach procedures is usually based on a position solution provided by satellite navigation systems in conjunction with inertial navigation systems, the vertical guidance is still based on measurements of a barometric altimeter. This type of approach with vertical guidance is supposed to enhance the situational awareness for pilots compared to non-precision approach procedures and reduce the risk for controlled flight into terrain. However, the accuracy of the barometric vertical guidance is inferior compared to precision approach procedures, temperature dependent and require the correct pressure setting for each approach in the aircraft. Therefore, novel curved approach procedures are supposed to rely solely on satellite navigation augmented by either a ground based or satellite based system and only optionally by inertial measurement systems. Such coupled (hybrid INS and GNSS) systems are usually highly integrated and monitored by a flight management system. Therefore, the requirements for the equipment of aircraft that are conducting such approach procedures are very stringent. Using only GBAS could relax those requirements. In this work, an option for precision curved approach procedures was investigated and tested in flight trials. This option is based on a GBAS. In general, different possibilities are imaginable to enable GBAS based curved approaches. For instance, GBAS could only serve as means to enhance the navigation performance to achieve stringent RNP requirements. Or GBAS could serve as the sole means to enable a curved approach. This option is described in this paper. Others include the Microwave Landing System or are conducted as a visual approach. The option which utilizes the GBAS functionality to broadcast desired (curved) flight paths, the Terminal Area Path (TAP) functionality was investigated in this work. For this, simulator trials were performed to evaluate different means of flying these procedures in terms of guidance displacement sensitivity and means of displaying deviation information. Based on the results of the simulator trials flight trials were conducted. Results from flight trials are presented in this manuscript to show how this method for conducting curved approaches can be applied.

Open Source GNSS Reference Server for Assisted-Global Navigation Satellite Systems

Abstract: Assisted-Global Navigation Satellite Systems (A-GNSS), or Assisted-Global Positioning Systems (A-GPS) in particular, are now commonly accepted as an effective way to reduce the time-to-first-fix (TTFF) in GNSS-unfriendly environments, e.g. in areas of weak GNSS signals. Today's location-based service (LBS) devices such as GPS-enabled mobile phones and personal digital assistants (PDA) rely on A-GPS; however, such commercial devices are equipped with an integrated A-GPS chip that makes customisation very difficult. The Open Source GNSS Reference Server (OSGRS) provided by the University of New South Wales is an open source Java application that can generate the necessary data for A-GPS clients. The GNSS Reference Interface Protocol (GRIP), based on extensible mark-up language (XML), is employed as the OSGRS interface protocol. This paper describes the current status of OSGRS: a client simulator is available open-source; client software which supports four different types of A-GPS-enabled receivers has been developed and used to test OSGRS. The performance of the OSGRS is analysed based on intensive tests. The challenges for OSGRS and future work are also discussed.

An Investigation of the Signal Performance of the Current and Future GNSS in Typical Urban Canyons in Australia Using a High Fidelity 3D Urban Model

Abstract: With the rapid development of spatial information infrastructure in US, Europe, Japan, China and India, there is no doubt that the next generation Global Navigation Satellite Systems ( GNSS) will improve the integrity, accuracy, reliability and availability of the position solution. GNSS is becoming an essential element of geospatial infrastructure and consequently part of our daily lives. However, the applicability of GPS in supporting a range of location-sensitive applications such as location based services (LBS) in an urban environment is severely curtailed by the interference of the 3D urban settings. No investigation has been carried out to accurately quantify and reliably evaluate the upcoming improvements like Galileo in typical 3D Australian urban environments.

SDR GNSS Receiver Design over Stand-Alone Generic TI DSP Platform

Abstract: Recent research on SDR (Software Defined Radio) GNSS receiver is mostly based on DSP/FPGA hybrid or PC platform. In this paper we will introduce a prototype design of SDR GNSS in stand-alone DSP platform. The GNSS receiver with has more than 12 GPS channels, which is implemented in a TI TMS320C6416 DSP chip. The chip will fulfill acquisition, tracking and positioning function in realtime. This method could be extended to other navigation constellation to archive multi- constellation GNSS receiver.

An Indoor-Outdoor Positioning System Based on the Combination of GPS and UWB Sensors

Abstract: Today localization techniques are gaining popularity because of the high interest for many business cases as well as for emergency/security scenarios including real-time tracking, navigation, clock synchronization … The need to obtain a precise position in a short time at any point, leads to use an efficient navigation system. In outdoor environments, GNSS (GPS, Galileo,...) is used and provide a good accuracy, but in the indoor environments, GNSS signal is deteriorated due to the signal degradation by different obstacles, so other techniques are used to locate users such as IR, RF, Cellular network or GNSS repeater. This paper provides a new design of Indoor-Outdoor positioning system based on the combination of data from UWB and GPS sources.