Link Budget Calculator

Estimate the received irradiance and power for a simple optical free-space link, from a mono-static terminal to a target range.

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System

The single aperture shared by the transmit and receive paths.

Transmitter

1.0 for a perfect, diffraction-limited beam.
3-sigma (or total budgeted) pointing error.

Path

Defaults to a typical LEO-LEO crosslink range — adjust for your own scenario.

Receiver

Loss between the shared aperture and the receiver's common optical path.
The common path splits between the acquisition/tracking sensor and the data detector; the remainder goes to acquisition/tracking.
Minimum optical power the data detector needs for the required data rate.

Transmitter result

Antenna gain –
Effective divergence (with clipping) –

Link budget result

M² loss –
WFE loss –
Free-space loss –
Pointing loss –

SDA receiver check

Irradiance at receiver aperture –
SDA threshold 25 µW/m²
Margin vs. SDA threshold –

Receiver result

Received power in common path –
To acquisition / tracking sensor –
To data detection –
Margin vs. required sensitivity –

Please enter valid numbers for all fields.