BACKGROUND
In urban environments, the accuracy of global navigation satellite systems (GNSS) like GPS is often compromised by non-line-of-sight (NLOS) errors. These errors occur when satellite signals are obstructed or reflected by buildings and other structures, leading to inaccurate positioning. Traditional methods to correct these errors, such as ray-tracing, simulate how signals interact with the urban landscape. However, these methods are computationally intensive and slow, making them unsuitable for real-time applications.
To address this challenge, researchers at University of Calgary developed a method called Pixel Shader Based Ray-Tracing (PSBRT). This approach leverages advanced graphics processing techniques and efficiently simulates signal reflections. By employing pixel shaders and a refinement process, the PSBRT method significantly reduces computational load with large-scale surfaces without introducing any additional error compared to the state-of-art method. This innovation allows for real-time NLOS error correction, enhancing GNSS positioning in complex urban settings.
AREAS OF APPLICATION
- Urban Navigation Systems
- Autonomous Vehicles
- Augmented Reality (AR)
- Disaster Response and Management
COMPETITIVE ADVANTAGES
- Real-time capability
- State-of-art accuracy
- Lower computational load
- Supports any surface shape and orientation
PUBLICATIONS AND RESOURCES
- Journal Publication: Zhitao Lyu & Yang Gao. Volume 27, article number 159, (2023). GPS Solutions
- Researcher profile: Dr. Zhitao Lyu & Dr. Yang Gao
- Lab website: Department of Geomatics Engineering