The decision you should be able to make
Produce defensible candidate mounting heights and a field-survey plan.
Core engineering
A digital elevation model describes sampled ground elevation; it normally does not prove roof, tree, crane or parapet height. Record the terrain data source, resolution and vertical datum.
Use antenna phase-centre height, not building height alone. Include roof level, support structure, mount offset and any known datum conversions.
Inspect the whole path for the governing clearance point. The midpoint has the largest Fresnel radius on a symmetric path, but the critical obstruction can be elsewhere.
Equipment and field checks
- Use a planning tool that exposes terrain source, effective-Earth-radius assumption and obstruction clearance rather than returning only a green/red result.
- Carry a calibrated method for measuring endpoint coordinates, mounting height and bearing; phone-only measurements may be insufficient for tight paths.
- Photograph both bearings and near-terminal clutter with identifiable reference heights.
Do not progress until
The profile includes terrain uncertainty, clutter notes, candidate phase-centre heights and a list of observations to confirm on site.
Limits and cautions
- A desktop line-of-sight result is a planning hypothesis, not proof of optical or radio clearance.
Primary sources
Sources were checked for this technical review. Recheck regulator and equipment requirements at the point of design or installation.