Tuesday, 6 September 2016

Calf Top (SD 664 856) – new 2,000ft mountain

Calf Top has been re-classified to a Hewitt based on the conversion of data from OSGM15, which is the Ordnance Surveys latest geoid model.

Alan Dawson announced the findings on the RHB Yahoo Group forum on 30.08.16 and announced his acceptance of Calf Top as a new Hewitt via a number of news outlets, including the Mail and the Express online.

Calf Top (SD 664 856) now a 2,000ft mountain and a new Hewitt

The reclassification of Calf Top to Hewitt status was based on two surveys conducted six years ago using precision levelling and GPS equipment by John Barnard, Graham Jackson and Myrddyn Phillips.  On the first visit a two hour data set was gathered, and on the second visit four hours of data were gathered, each data set was sent to Ordnance Survey.  The result when Ordnance Survey processed the data through Bernese software was 609.58m, just 2cm below 609.6, or in imperial terms, less than one inch below 2,000ft.

The new geoid model (OSGM15) produced by Ordnance Survey have increased known heights in both England and in Wales by around 2 – 4cm, meaning that Calf Top nudges past the 609.6m / 2,000ft benchmark height by 6mm.

The news that Calf Top is a new 2,000ft mountain has been reported on various websites, and in a number of national newspapers, including:

The Times

This morning's Daily Mirror

No comments: