Height of the receiving antenna above ground. Default 1.8m = handheld at chest height.

Fraction of time the signal will be strong enough.
70% = works most of the time. 90%+ = very conservative.

Fraction of locations where coverage will be as predicted.
70% = correct for most locations. For most planning: use 70 / 70.

Models vegetation and man-made obstructions by uniformly raising the terrain surface across the coverage area.

The ITM model uses bare-earth elevation data and does not account for trees or buildings. Adding clutter height makes the simulation more conservative by treating the landscape as if it were that much taller — reducing predicted coverage to better reflect real-world conditions.

0 m   — open terrain, no obstructions (default)
8–10 m — forested or suburban areas
15–20 m — dense forest or urban areas

Note: clutter is not applied at the transmitter location or over open water. Higher values will reduce coverage area.

An adjustment that may be necessary at certain locations where elevation data quality is reduced — for example near coastlines, small islands, or areas with complex terrain transitions.

In such locations the propagation calculation can produce ray artifacts: anomalous spikes or streaks radiating from the transmitter site that do not reflect actual coverage. Setting a terrain clearance value of 10–20 m typically suppresses these artifacts without significantly affecting the overall coverage pattern.

0 m   — no adjustment (default, use for most locations)
5–10 m — minor correction, coastal or island sites
15–25 m — stronger correction if artifacts persist

Leave at 0 unless you observe artifacts in the coverage map.