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Improving GNSS Accuracy in Urban Settings

A new method enhances GNSS location accuracy in cities with tall buildings.

― 4 min read


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Table of Contents

Global Navigation Satellite System (GNSS) helps determine the location of devices like smartphones and cars. However, in busy cities with tall buildings, signals from satellites can get blocked, leading to mistakes in location estimates. To fix this problem, a new method that combines advanced computer techniques with these positioning systems has been developed.

The Problem with GNSS in Urban Areas

In urban settings, buildings obstruct direct signals from GNSS satellites. This blockage results in errors when measuring distances to these satellites. These errors can make it tough for devices to know where they are. Traditional methods often used to deal with this problem involve guesswork, estimating how off these measurements might be and trying to fix the final position based on that guesswork.

Introducing a Smarter Solution

This new method replaces the guesswork with a model that utilizes Deep Learning, which is a special kind of artificial intelligence (AI). The deep learning model analyzes satellite data and can predict where the errors are occurring in distance measurements. This approach not only estimates the errors more accurately but also allows the calculations for location to be more precise.

How the New Method Works

  1. Error Estimation: The new model uses a special technique called a Graph Neural Network (GNN). This model looks at data from multiple satellites at the same time and learns from it. By making connections between the various signals, it can better estimate how far off the distances might be.

  2. Cost Function Regulation: The method then focuses on regulating the way errors influence the cost of potential locations. By adjusting the way these errors are considered, the model ensures that the most accurate location is identified, even if individual measurements are not perfect.

  3. Measurement Selection: Finally, the method includes a way to choose only the best measurements to use for determining location. By filtering out poor-quality signals, the model improves the accuracy of its final positioning.

Testing the New Method

The new approach has been tested using real-world data collected in multiple cities. The dataset includes a wide range of scenarios, from open skies to densely built areas. The model was trained using this data and then evaluated in different conditions, ensuring that its effectiveness would not change depending on the environment.

Results of the Testing

The results of implementing the new method were very promising. Compared to traditional approaches, the new method provided significant improvements in measurement accuracy. In many cases, it reduced errors by as much as 80% when compared to older methods that relied on simple averages and guesswork.

Why Does This Matter?

Improving GNSS positioning is crucial for many applications. Whether for navigation in cars, delivering packages, or even safety measures like emergency services, accurate positioning helps reduce errors and improve efficiency.

Understanding the Components of the New Method

  1. Graph Neural Networks: These are models designed to work with data represented as graphs. In GNSS, each satellite can be seen as a node in a graph, and the connections between them can be based on various factors like proximity and signal strength. By using GNNs, the model can analyze relationships between satellites and their signals more effectively.

  2. Cost Functions: In mathematics and statistics, cost functions quantify how far an estimated position is from the actual one. By controlling how these costs are calculated, the model ensures that it is more precise in finding the best location.

  3. Measurement Selection Algorithms: These algorithms help determine which signals to trust and use when calculating position. By discarding weak signals, the model ensures that it only relies on the most reliable data.

Real-World Applications of Improved GNSS

With GPS and GNSS technology used in countless applications today, ranging from personal devices to large-scale logistics and transportation systems, efficiency and accuracy are paramount. This new method can help:

  • Navigate Cars: By giving accurate location data, drivers can find the best routes and avoid traffic, saving time and fuel.

  • Plan Deliveries: Companies can improve delivery times and efficiency by knowing exactly where packages are and how to get them to customers.

  • Enhance Safety: In emergencies, knowing accurate locations can help responders reach their destinations faster and more effectively.

Conclusion

In conclusion, the combination of deep learning, cost function regulation, and measurement selection presents a powerful new tool for improving GNSS positioning in urban areas. By addressing the challenges posed by high-rise buildings and signal blockages, this innovative approach offers solutions that can make a meaningful impact in various real-world applications. As the world becomes increasingly reliant on accurate positioning data, advancements like these pave the way for more effective GPS usage and smarter navigation technologies.

Original Source

Title: GNSS Positioning using Cost Function Regulated Multilateration and Graph Neural Networks

Abstract: In urban environments, where line-of-sight signals from GNSS satellites are frequently blocked by high-rise objects, GNSS receivers are subject to large errors in measuring satellite ranges. Heuristic methods are commonly used to estimate these errors and reduce the impact of noisy measurements on localization accuracy. In our work, we replace these error estimation heuristics with a deep learning model based on Graph Neural Networks. Additionally, by analyzing the cost function of the multilateration process, we derive an optimal method to utilize the estimated errors. Our approach guarantees that the multilateration converges to the receiver's location as the error estimation accuracy increases. We evaluate our solution on a real-world dataset containing more than 100k GNSS epochs, collected from multiple cities with diverse characteristics. The empirical results show improvements from 40% to 80% in the horizontal localization error against recent deep learning baselines as well as classical localization approaches.

Authors: Amir Jalalirad, Davide Belli, Bence Major, Songwon Jee, Himanshu Shah, Will Morrison

Last Update: 2024-02-28 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2402.18630

Source PDF: https://arxiv.org/pdf/2402.18630

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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