Ground Station & Satellite
Ground Station Settings
Satellite Preset & TLE
Radio & Audio Settings
Real-Time Footprint & Sky Track
Tracking: Active
Ground Station Local Horizon (Radar view)
Telemetry & Pass Schedule
Elevation
-- °
Azimuth
-- °
Range
-- km
Range Rate
-- km/s
Doppler Shift
-- kHz
RX Frequency
-- MHz
Pass Simulation: Idle
IDLE
Time Warp:
Upcoming Passes (Next 24h)
| AOS (Local) | Duration | Max El | Direction |
|---|---|---|---|
| Loading pass predictions... | |||
Pass Analysis S-Curve
Radio Doppler Shift & LEO Tracking
Low Earth Orbit (LEO) satellites travel at extremely high relative velocities ($\approx 7.5\text{ km/s}$ at $\approx 600\text{ km}$ altitude) to counteract gravity. Due to the **Doppler Effect**, electromagnetic waves emitted by an approaching satellite appear compressed (frequency shifted upward), while waves from a receding satellite appear stretched (frequency shifted downward). Radio transceivers must adjust their tuning in real time to match this S-curve frequency drift, which sweeps steepest when the satellite reaches its **Closest Approach (TCA)** and the range rate swings from negative to positive.