Evaluation of the Multipath Environment Using Electromagnetic-Absorbing Materials at Continuous GNSS Stations

Area of Science:

• Geomatics Engineering
• Satellite Navigation Systems
• Signal Processing

Background:

• Site-specific multipath errors degrade high-precision Global Navigation Satellite System (GNSS) data accuracy.
• Multipath interference affects both carrier-phase and code/pseudorange measurements, leading to position biases.
• Existing universal modeling techniques for mitigating multipath effects are insufficient.

Purpose of the Study:

• To evaluate the effectiveness of Eccosorb AN-W-79 microwave-absorbing material in reducing GNSS multipath errors.
• To quantify the impact of the material on positioning accuracy and signal quality across multiple GNSS constellations.

Main Methods:

• Installation of two co-located multi-GNSS (BeiDou, GLONASS, Galileo, GPS) stations in a challenging environment.
• One station equipped with Eccosorb AN-W-79 material (3.35 m² coverage), the other serving as a control.
• Analysis of standard deviation reductions in single-point positioning, code/carrier phase measurements, and post-fit residuals.

Main Results:

• Significant standard deviation reductions in single-point positioning for all GNSS: GPS (15-23%), Galileo (22-45%), GLONASS (22%), BeiDou (4%).
• Substantial reduction in code multipath: Galileo (>60%), GLONASS (up to 50%), BeiDou (>30%), GPS (20-40%).
• Improvement in carrier phase cycle slips (15-60%) and reduction in RMS of post-fit residuals (Galileo: 13%, GLONASS/GPS: 9%).

Conclusions:

• Eccosorb AN-W-79 microwave-absorbing material effectively mitigates GNSS multipath noise.
• The material demonstrates a capacity to lessen multipath influence, leading to improved positioning accuracy and signal stability.
• Further research may explore optimized material application and integration for complete multipath elimination.