How it works
Line of sight means that the direct route between antennas is not blocked by an obstacle. Wireless planning also considers space around that route, often described using the Fresnel zone. A narrow visual gap between roofs or branches may therefore be insufficient even when one antenna can be seen from the other.
Important differences and limits
Trees can change with growth, wind and wet foliage; vehicles or new structures may obstruct a low installation. Raising power does not remove an obstruction. The importance of clearance depends on the frequency, distance and equipment, so a photograph alone is not a complete radio assessment.
A useful practical check
Inspect the path from the proposed antenna positions, not just from ground level. Identify seasonal vegetation and possible future obstructions. Assess the equipment’s clearance guidance and alternative mounting points. Confirm the result with an aligned link and real traffic measurements before relying on it for work, cameras or other continuous use.
An example in practice
A gap that looks clear in winter may fill with leaves in summer. The proposed installation should account for that change rather than rely on the day’s photograph. Comparing mounting heights and alternate paths can reveal a more dependable route before equipment is permanently fixed. A site assessment should record the planned mounting positions so future inspection evaluates the same path.