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Featured · Technical Deep-Dive
Tienstra Resection: Understanding the Danger Circle and When to Reposition
The Tienstra method is one of the most elegant solutions in surveying mathematics — but it carries a geometric trap that has caused field problems for generations of surveyors. Understanding the danger circle is not optional.
Gordon McInnes, FInstCES
2026-01-15 · 8min read · 23 comments
Project Spotlight
How We Set Out the Gateshead Millennium Bridge to ±2mm
The Gateshead Millennium Bridge required setting out a 105-metre tilting arch to millimetre tolerances — in a tidal zone…
A. Reid, MRICS · 12min · 41 comments
Technical Deep-Dive
GSI-8 vs GSI-16: Which Format Should You Be Using in 2026?
GSI-8 and GSI-16 have coexisted for decades in the Leica ecosystem. With modern total stations defaulting to GSI-16, und…
surveyiiing.com · 5min · 18 comments
Standards & Compliance
NSSS 6th Edition — What Changed and What It Means for Column Setout Tolerances
The 6th Edition of the National Structural Steelwork Specification introduced revised positional tolerances for column b…
D. Okafor, CEng · 10min · 9 comments
Field Notes
Field Notes: Running a Traverse on a Live Construction Site
A live construction site is one of the most hostile environments for precision surveying. Vibration, obstructions, perso…
M. Fenton · 6min · 31 comments