Quarterly Progress Update –  RedFrog & RTU Project
Reporting period: 01.12.2025 – 28.02.2026

During this reporting period, the project continued advancing the development of a hybrid indoor positioning system, focusing on the integration and evaluation of BLE Angle-of-Arrival (AoA) and ultrasonic localization technologies.

BLE AoA System Evaluation

Initial laboratory testing of commercially available BLE AoA solutions was carried out to assess real-world positioning accuracy. The study identified key technical limitations related to antenna array configurations, signal stability, synchronization between nodes, and power consumption. These findings are used to refine the role and architecture of the BLE subsystem within the hybrid localization framework.

Ultrasonic Localization Development (DP3)

Work has started on the research and simulation of an ultrasonic positioning subsystem.

Key activities include:

• A comprehensive literature review on ultrasonic phased arrays, beamforming, and beam steering techniques;
• Evaluation of array configurations (linear and planar) for indoor positioning applications;
• Definition of initial system parameters such as element count, spacing, operating frequency, and steering range;
• Development of MATLAB simulation models for beamforming and steering, including delay law calculations and array performance analysis.

Signal Processing Research (Chirp Signals)

Research has also begun on nonlinear chirp signals for time-of-flight measurements. The team is analyzing how chirp parameters affect distance estimation accuracy and is exploring frequency downconversion techniques to adapt ultrasonic signals to receiver constraints. Initial criteria for optimal signal design have been defined to support accurate and efficient data transmission.

Summary

This phase of the project focused on validating foundational technologies and developing simulation models for a next-generation hybrid indoor localization system. The results provide a strong basis for further prototyping and system optimization.

This project marks an important milestone toward next-generation precise indoor localization technologies in Latvia and beyond.

#RedFrog #RTU #EU #Grant #Innovation #Research #Ultrasound 🚀🐸