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The advent of modernized and new global navigation satellite systems (GNSS) has enhanced the availability of satellite based positioning, navigation, and timing (PNT) solutions. Specifically, it increases redundancy and yields operational back-up or independence in case of failure or unavailability of one system. Among existing GNSS, the Chinese COMPASS navigation satellite system (CNSS) and the European Galileo system are being developed. In this contribution, a COMPASS/Galileo/GPS robustness analysis is carried out for instantaneous, unaided attitude determination. Precise attitude determination using multiple GNSS antennas mounted on a platform relies on the successful resolution of the integer carrier phase ambiguities. The constrained Least-squares AMBiguity Decorrelation Adjustment (C-LAMBDA) method has been developed for the quadratically constrained GNSS compass model that incorporates the known baseline length. In this contribution the method is used to analyse the attitude determination performance when using the GPS, the Galileo, and COMPASS systems. The attitude determination performance is evaluated using GPS/Galileo/COMPASS data sets from a real data campaign in Australia. The study includes the performance analyses of both stand-alone and mixed constellation (GPS/Galileo/COMPASS) attitude estimation under satellite outage. We demonstrate and quantify the improved availability, reliability, and accuracy of attitude determination using the combined constellation. [ABSTRACT FROM PUBLISHER]

Nowadays, many vehicles are equipped with GPS navigation systems, that are accurate to approximately 10 meters. This is insufficient to determine the lane a vehicle is driving in. We introduce a new technique, Precise Point Positioning, which is able to get the accuracy of measurement down to approximately half a meter, without having to resort to expensive high-end GPS receivers. This accuracy is possible with a single measurement of position in real-time. We confirm this accuracy in a real-life test with a vehicle driving at motorway speeds. However, even when the vehicle position is known, the driving lane is not known since there are generally no maps with detailed lane information. Therefore, this paper also presents a self-learning method, using this Precise Point Positioning information, to create maps which include the position of lanes. This method is tested using an artificially created dataset, using the accuracies from the real-world test. This shows that the method can get the position of a lane at an accuracy of 20 cm. The combination of accurate information of the position of a vehicle and information about the position of the lane, can be used to give lane-specific advice for drivers, and can even be a step towards automated driving. [ABSTRACT FROM PUBLISHER]

The proliferation of Global Navigation Satellite Systems (GNSS) paves the way for an increasing number of applications in positioning, guidance and navigation. GNSS-based attitude determination is one of such an important and promising application. In this contribution we explore the potential of GNSS-based attitude determination for Low Earth orbiting (LEO) formation flying Synthetic Aperture Radar (SAR) satellites. Precise attitude determination using multiple GNSS receivers/antennas relies on a successful resolution of the integer carrier phase ambiguities. For a set of rigidly satellite-mounted GNSS antennas, a number of nonlinear geometrical constraints can be exploited for the purpose of increasing the probability of correct integer ambiguity estimation. In this contribution, we make use of the Multivariate Constrained Least-squares AMBiguity Decorrelation Adjustment (MC-LAMBDA) method. By incorporating the known antenna geometry into its ambiguity objective function, this method is shown to demonstrate reliable and instantaneous single-frequency integer ambiguity resolution. The resulting attitude estimates are further improved using nonlinear filtering. Our hardware-in-the-loop experiment with the University of New Sourth Wales “Namuru” GNSS receivers shows the potential of stand-alone, unaided, single-frequency attitude determination of LEO satellites. [ABSTRACT FROM PUBLISHER]