Tools : Range Calculator

Plan your link.
Estimate before you fly.

A link-budget estimator for CY-2-class radios. Pick your antennas, altitude, terrain, and bandwidth: get an estimated reliable range, link margin, throughput mode, Fresnel clearance, and the radio horizon.

Planning value only. Real field performance depends on antenna mounting, RF noise, regulatory power limits, channel width, obstructions, polarization, and alignment. Treat all numbers as estimates, not guarantees.

Link margin

+5.5dB

at 5.0 km : vs -94 dBm robust mode

Received power

-88.5dBm

at 5.0 km

Throughput estimate

6Mbps

Stable telemetry + video : below planning margin

Link margin vs distance

Reliable margin against the most robust mode

Good (> 10 dB)Marginal (3-10 dB)Unreliable (< 3 dB)
-20-100+10+20+30Margin : dB024681012Distance : kmRequired fade margin : 10 dB3.7 km5.0 km : 5.5 dB

Fresnel clearance

4.8 m needed

Path midpoint clears 60% of the first Fresnel zone at the selected distance (8.0 m radius). Visual LOS plus this clearance is the planning baseline.

Radio horizon

50.9 km cap

Earth curvature does not limit the link at the planned range. Increasing altitude pushes the horizon further out (50.9 km available).

Regulatory

29 dBm EIRP @ 2 dBi

EIRP at the air unit is ≈ 30.2 dBm. Verify against your local authority's limits for the 5.8 GHz band: many regions cap unlicensed operation at 30-36 dBm EIRP.

Link budget at 5.0 km

All terms in dB : running total = received power

Tx power+29.0 dBm
Air antenna gain+2.0 dB
Ground antenna gain+8.0 dB
Air cable loss-0.8 dB
Ground cable loss-1.0 dB
Free-space path loss-121.7 dB
Terrain / obstruction-0.0 dB
Polarization loss-0.5 dB
Misalignment loss-1.0 dB
Implementation loss-2.5 dB
Received power-88.5 dBm
Robust-mode sensitivity (20 MHz)-94 dBm
Link margin+5.5 dB