Sight distance

Sight Line vs. Ground Profile

Plot measured ground elevations against a straight sight line and review the vertical clearance.

Sight line & ground

Use elevations on the same vertical datum. Include the eye and target heights above their ground elevations.

Eye point elevation (ft) Target point elevation (ft)

Enter total elevations, not just heights above the ground.

Total distance, eye to target (ft) Ground points: distance, elevation (ft)

One pair per line, separated by a comma or tab. You can paste two columns from a spreadsheet. The header is optional. Distances start at the eye, stay within the total distance, and must be unique. Points are sorted automatically.

Initial values are an illustrative example. Results update as you type.

Ground comparison

Minimum entered-point clearance

Ground points

Sight lineGroundGround above lineHorizontal and vertical scales differ.

Scroll the chart and results table horizontally to see all values.

Point clearances

Clearance = sight line elevation − ground elevation. Negative values mean the ground is above the sight line; zero means it touches.

Ground points sorted by distance from the eye; all values in feet
Distance (ft)	Ground (ft)	Sight line (ft)	Clearance (ft)	Position

How the comparison works

The sight line uses Z(x) = Z_eye + (Z_target − Z_eye) × x / L. Ground segments connect your measured points. Shading stops at the calculated crossings of each ground segment and the sight line.

Results cover the entered points and the straight segments between them. Unmeasured ground, vegetation, and other objects are not represented; this plot does not establish that the full sight path is clear.