A Geometric Approach to Instrument Landing System Modeling and Simulation
11th International Conference on Recent Advances in Air and Space Technologies, Conference Program, RAST 2026, İstanbul, Turkey, 13 - 15 May 2026, (Full Text)
- Publication Type: Conference Paper / Full Text
- Doi Number: 10.1109/rast69551.2026.11672442
- City: İstanbul
- Country: Turkey
- Keywords: approach geometry, difference in depth of modulation (DDM), glideslope (GS), instrument landing system (ILS), localizer (LOC), marker beacon (MB)
- Yıldız Technical University Affiliated: Yes
Abstract
This paper presents a geometric modeling approach for the Instrument Landing System (ILS), focusing on the generation of localizer, glideslope, and marker beacon indications based on aircraft and ground station geometry. Aircraft and ILS station positions are represented in WGS-84 coordinates, and geodetic distances are computed using Vincenty's inverse method. Lateral and vertical guidance cues are derived from bearing and elevation-based geometric relationships referenced to the runway true course and nominal glideslope angle, without employing frequency-domain signal analysis. Although the proposed model does not perform frequency-domain signal analysis, standard ILS frequency assignments are used for station identification and system configuration. The proposed model is implemented and validated in a flight simulation environment using X-Plane 12, demonstrating close agreement with reference instrument indications during approach scenarios. The results confirm the suitability of the geometric approach for ILS simulation and navigation system analysis.