9:30 AM - 9:45 AM
[G05-1-05] Global GNSS processing based on the raw observation approach
High-quality global navigation satellite system (GNSS) products, such as precise satellite orbits and clocks, are a requirement for many GNSS applications, e.g. Precise Point Positioning. These products are routinely determined by analysis centers of the International GNSS Service (IGS). In their GNSS processing, these analysis centers make use of the ionosphere-free linear combination to reduce the ionospheric influence. Some of the analysis centers also form observation differences, in general double-differences, to eliminate several additional error sources. The raw observation approach is a new GNSS processing approach that was developed at Graz University of Technology for kinematic orbit determination of low Earth orbit (LEO) satellites and for processing a global ground station network. The raw observation approach offers some benefits compared to well-established approaches, such as a straightforward incorporation of new observables due to the avoidance of observation differences and linear combinations. This becomes especially important in view of the changing GNSS landscape with two new systems, the European system Galileo and the Chinese system BeiDou, currently in deployment.
Graz University of Technology currently generates the following GNSS products using the raw observation approach: precise satellite orbits and clocks, station positions and clocks, code and phase biases, and Earth rotation parameters. The new approach is evaluated by comparing products generated using the Global Positioning System (GPS) constellation and observations from the global IGS station network to the GNSS products of IGS analysis centers. The comparisons show that the products determined at Graz University of Technology are on a similar level of quality to the IGS analysis center products. This confirms that the raw observation approach is applicable to global GNSS processing. Some areas requiring further work have been identified, enabling future improvements of the method.
Graz University of Technology currently generates the following GNSS products using the raw observation approach: precise satellite orbits and clocks, station positions and clocks, code and phase biases, and Earth rotation parameters. The new approach is evaluated by comparing products generated using the Global Positioning System (GPS) constellation and observations from the global IGS station network to the GNSS products of IGS analysis centers. The comparisons show that the products determined at Graz University of Technology are on a similar level of quality to the IGS analysis center products. This confirms that the raw observation approach is applicable to global GNSS processing. Some areas requiring further work have been identified, enabling future improvements of the method.