This article makes the case that DGPS — providing decimetric horizontal positioning accuracy — is insufficient for modern shallow-water multibeam surveys where IHO Special Order specifications apply. The positioning error budget in shallow water is dominated by horizontal position uncertainty, and centimetre-level GNSS is both available and affordable.
Technical note — Positioning
Stop Using DGPS!
Originally published in Hydro International in 2012 — why decimetric positioning is insufficient for shallow-water hydrographic surveys, and what to use instead.
2024 Update
- In 2012, SBAS corrections were typically accurate to ~0.5 m in the horizontal axes.
- Since this article first appeared, commercial SBAS accuracies have improved by an order of magnitude.
- The article covered shallow-water surveying, yet never specifically stated the topic was limited to surveys where IHO Special Order specifications applied.
- Today's more appropriate title is "Stop Using Decimetric+ Positioning in Shallow Water Surveys!"
Original article — Hydro International, 2012
Stop Using DGPS! — M. Brissette
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Centimetre-level SBAS services
