Analysis on Spherical Signal Coverage of Navigation Based on Digital Twin

This paper studies the signal coverage of navigation equipment with equal high-level characteristics at a certain flight altitude, namely in contour plane. The real localizer antenna array system was simulated by the design of digital twin. The horizontal pattern and the vertical pattern of antenna array were researchedconsequently, the space electromagnetic radiation model was established. When aircraft is fling in wide area, there are obvious differences between two dimension plane and contour plane. Considering the geometric shape of the spherical characteristics of Earth, the geometric error and signal deviation caused by the Earth curvature were revised. Four contour plane flight levels (H = 200 m, 400 m, 600 m and 800 m) were established. The circumstances of coverage in the aircraft approach area is analyzed one by one. Also, four conditions were compared with fight checking by signal strength and coverage. The results showed that the electromagnetic signal provided by the localizer beacon is enough to meet the coverage requirements at the approach altitude. The higher the altitude, the larger the coverage zone. Under the low altitude H = 200m, it starts to appear coverage insufficient in different azimuth angles. Consequently, this analysis method of spherical signal features provides an effective research method for subsequent navigation coverage analysis.