Ben Nevis gains a metre thanks to GPS height measurement

Following the restoration of the trig pillar, and the cairn on which it sits on Ben Nevis, Ordnance Survey (OS) took the opportunity to re-measure the iconic mountain’s height.

Can a mountain really grow?

The change in height is mostly down to new technology which OS now uses to survey and measure. This technologic advancement gives a greater measurement accuracy compared to when Ben Nevis was last surveyed in 1949.

Three members of the Geodesy & Positioning team, two of which are RICS professionals, occupied the summit's pillar with a survey grade GNSS receiver and recorded two hours of static GNSS observations. While this was recording the observations, a levelling survey of the summit was performed to determine the highest natural point. All levelled heights were relative to the trig pillar bench mark.

Mark Greaves MRICS was responsible for processing the GNSS data to the highest possible accuracy. This meant using the scientific Bernese Software and advanced analysis techniques.

The Ben Nevis data was combined with matching GNSS data from the nearest six OS Net permanent GNSS reference stations along with precise satellite orbits and other high accuracy post processing products such as Earth rotation parameters.