Bizkaia NAP Network

The Bizkaia High Precision Leveling Network (NAP) is part of the geodesic infrastructure of the Historical Territory of Bizkaia. It densifies the REDNAP Project of the National Geographic Institute (IGN), which in turn links with the European vertical reference models EUVN. The new sections being carried out by the BFA/DFB are consistent with IGN's REDNAP specifications and qualities. The Historical Territory of Bizkaia therefore has a network of heterogeneous levelling signals in which IGN nails, new DFB nails and Basque Government nails survive (in non-current altimetric frames) that are being re-observed in the NAP densification campaigns.