Real-World LFR Navigator — Cone of Silence

Status: Ready — Click START or use Desktop Test Mode below

Top-down view • Beacon at center • Yellow = beams • Dashed red = cone of silence footprint

Live Telemetry

Horizontal distance: — m

Height above beacon: — m

Slant range: — m

Angle from vertical: —°

Bearing from beacon: —°

A intensity: 0.00
N intensity: 0.00
Total volume: 0.00

Quick test position offsets (relative to beacon)

Type coordinates below or use the quick offset buttons. No need to click Apply — it updates live.

Your Test Latitude

Your Test Longitude

Tip: Set beacon altitude negative (e.g. -25) for ground testing. Use manual altitude ~2–5 m.

Beacon Latitude

Beacon Longitude

Beacon Altitude (m) — negative = below ground for field testing

Reference Bearing (°) — rotates all four beams (0° = N/S/E/W)

Max Usable Slant Range (m)

Field/walking: 150–600 m | Aircraft: 20,000–100,000 m

Cone of Silence Half-Angle (°) from vertical

5° (narrow) 28° 60° (wide)

My Altitude Mode

Use GPS altitude when available

Manual Altitude Override (m MSL)

For field testing: beacon alt = -25 to -40, manual alt = 2 to 8 m

Click/tap once to enable audio (browser requirement). On iOS enable Precise Location for the browser.

Desktop testing (recommended first step): Click "Load Demo (~200m North)" in the blue test panel above, then click START AUDIO. You should hear sound immediately and see telemetry update.
Use the quick offset buttons (N/S/E/W) to move your test position around the beacon and hear how the A/N signals change.
iOS / real GPS: Tap START, allow location, then walk or drive. Make sure Precise Location is enabled in Settings → Privacy → Location Services → [Browser].
Adjust beacon altitude (negative for ground tests), max range, and cone angle live — everything updates in real time.
Cone of Silence: When you are nearly overhead (within the cone angle), volume fades to zero. This is the classic station passage cue.
Steady tone: When you are on one of the four beams, A and N overlap perfectly → continuous tone with no gaps.

Note: Phone GPS altitude is often inaccurate (±10–30 m). For real aircraft use, feed better altitude data if possible.