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🛰️ Doppler Shift Calculator

Calculate Doppler-corrected uplink and downlink frequencies for satellite passes. Enter your frequencies and satellite velocity to find the adjusted transmit/receive values.

Frequencies

Satellite Velocity

Enter the radial velocity (positive = approaching, negative = receding). Your satellite tracker (Gpredict, Orbitron) shows this in real time.

Results Stationary

Doppler Shift (Downlink)
0.000 Hz
Adjusted RX Frequency (tune radio to)
145.800000 MHz
Doppler Shift (Uplink)
0.000 Hz
Adjusted TX Frequency (transmit on)
144.490000 MHz
How to use:
Load a satellite from the table below. During a pass, enter the real-time radial velocity from your tracking software, or use altitude + elevation mode for an estimate. The Adjusted RX is what you tune your SDR/radio to. The Adjusted TX is what you transmit on so the satellite receives the correct frequency.

Common Satellites — Click to Load

SatelliteAlt (km)DownlinkUplinkModeNotes