Board to draft advisory opinion urging use of signed, sealed surveys over raw LiDAR data

The engineering committee agreed Dec. 5 to develop a short advisory opinion warning registrants that LiDAR and other third‑party elevation products can be inaccurate and that sign‑and‑sealed field surveys should be the basis for sealed civil design work.

Jason Carter, board chair, raised concerns about engineers using LiDAR or publicly available datasets as a substitute for a field survey. "I've heard stories of engineers using that as the basis for design instead of using an actual field survey," Carter said, arguing that registrants must understand the risk when they place their professional seal on work that relied on third‑party remote data.

Committee members described technical differences between LiDAR processed in MicroStation and AutoCAD, and discussed how trees and overhangs can cause significant errors in some workflows. A staff member noted that in practice engineers often use LiDAR for preliminary alignment and planning but perform a field survey before signing and sealing final construction documents. "You get a relatively close idea, but we know it may or may not be accurate. So we always do the field survey," said a committee member.

The committee asked Jason Carter to draft concise language (a short technical opinion) and agreed to route it through staff to send to the Tennessee Surveyors Licensing Board for peer review before any formal publication. Staff said the opinion would likely be posted in the board’s reference manual and shared with registrants at the next meeting for a formal vote if needed. Committee members emphasized the opinion should be advisory, not regulatory: "It's not law. It's not a rule. It's just a recommendation," Carter said.

Why it matters: improved clarity on acceptable data sources for sealed design work reduces risk for engineers and public‑safety exposure if design calculations rely on inaccurate surface data.

Next steps: Carter will draft the proposed text, staff will circulate it to the surveyors licensing board for review, and the committee will consider formal adoption at a future meeting or via the board reference manual.

Provenance evidence: committee discussion of mapping/LiDAR and the plan to draft an opinion appears in the engineering committee discussion during the morning session of the Dec. 5 meeting.