GNSS, GIS and data0 answersAI answer
A client compared our state plane distances with taped ground distances and found differences.
Asked October 25, 2026
AI answer · not yet verified by a surveyor
That difference is expected. It comes from the combined scale factor, which combines the grid (projection) scale factor and the elevation factor [1].
Practical steps:
- Tell clients which distances you report: grid or ground, and the factor used.
- Choose a system for the project: state plane grid, a low-distortion projection, or a scaled ground system with a stated origin and factor.
- Note it on the plat: basis of bearings, datum, units, and the combined factor if distances are scaled.
- Stay consistent: design, staking and as-builts should all use the same system.
- Watch the units: with the move to new reference frames and the international foot, confirm the foot definition [2].
Most disputes over distances disappear once the basis is clearly stated.
General information only. Answers here are not a survey or legal advice, and no one here can tell you where your boundary is. For your property, hire a licensed land surveyor in your state; for legal questions, a real-estate attorney.