Sculthorpe airfield, Norfolk. Photo: Helen Hanley CC-BY-SA-2.0

Ofcom has warned of another jamming exercise affecting Global Positioning System signals.

GPS receivers may be affected within 2km of the Sculthorpe airfield near Fakenham in north Norfolk.

The jamming exercises will take place between 6 and 10 February next year at the RAF base, which formerly housed both British and US bombers but is now used for Army helicopter training and low-level exercises by special-operations aircraft from the United States Air Force.

The Government’s official telecommunications body warned walkers and other outdoor enthusiasts GPS signals may be blocked between 7am and 5pm during the exercises, and conventional navigational techniques – using map and compass – will be necessary.

The airfield lies 10km (6 miles) east of the Peddars Way and there is a handful of rights of way that may be in the zone affected by the jamming signals.