The Tellus Border project is a €4.8M EU INTERREG IVA-funded cross border project designed to map the environment and geology of the border region of Ireland. The lead partner on this project is the Geological Survey of Northern Ireland (GSNI) in partnership with the Geological Survey of Ireland (GSI) and is an extension of the Tellus project carried out in Northern Ireland in 2005 and 2006. The airborne part of the project comprises the collection of low altitude magnetic, spectrometry and frequency domain electromagnetic data. The airborne survey was carried out by Sander Geophysics Ltd (SGL 2012b). The survey aircraft was based in St Angelo’s Airport, Enniskillen, NI although low level surveying was only carried out in the Republic of Ireland. Surveying took place primarily over the 6 northern counties of the Republic namely Donegal, Leitrim, Sligo, Cavan, Monaghan and Louth. The airborne survey commenced in September 2011 with the testing and calibration of equipment. The first full production flight took place on 26th October 2011 the last flight occurred on 15th July 2012 approximately 9 months after the first flight. Poor weather slowed the progress of the survey. The quality assessment of data was carried out by staff from GSNI and GSI throughout the duration of the survey with final sign-off and order for demobilisation of the aircraft and crew on 22nd July 2012.