none 10.1190/1.2163912 Society of Exploration Geophysicists Society of Exploration Geophysicists 186 19415827 5981 2025121112531950200 10.1190 2025-12-11T17:53:22Z 2006-01-26T11:50:43Z 38 Geophysics 1942-2156 0016-8033 2006 01 01 2006 71 1 Eirik Mauring 1Geological Survey of Norway, 7491 Trondheim, Norway. E-mail: eirik.mauring@ngu.no. Ola Kihle 1Geological Survey of Norway, 7491 Trondheim, Norway. E-mail: eirik.mauring@ngu.no. Abstract We describe a new technique that can be used to level data collected along regular and irregular line patterns with or without tie-line control. The technique incorporates a moving differential median filter to minimize line-level errors, to level survey-line data, and to micro-level data with no tie-line control. This overcomes the problem of standard leveling methods that lose their effectiveness with irregular flight patterns. To validate the method, we use it to level very-low-frequency (VLF) electromagnetic (EM) data from a helicopter survey where flight lines are parallel. Leveling is also performed on a set of vintage aeromagnetic data from the North Sea, gathered from nonparallel flight lines. Results show that the differential median filter leveling technique is superior to the standard leveling method because it results in fewer line errors and less distortion of high-wavenumber anomalies when proce-ssing irregular survey lines, making the method suitable for a wide variety of data sets. 2006 01 01 2006 12 19 2005 L5 L11 10.1190/1.2163912 https://pubs.geoscienceworld.org/geophysics/article/71/1/L5/249067/Leveling-aerogeophysical-data-using-a-moving https://pubs.geoscienceworld.org/seg/geophysics/article-pdf/71/1/L5/3206761/gsgpy_71_1_L5.pdf https://pubs.geoscienceworld.org/seg/geophysics/article-pdf/71/1/L5/3206761/gsgpy_71_1_L5.pdf http://geophysics.geoscienceworld.org/cgi/doi/10.1190/1.2163912 Geophysics Briggs 39 39 1974 10.1190/1.1440410 Machine contouring using minimum curvature Geophysical Prospecting Ferraccioli 46 177 1998 10.1046/j.1365-2478.1998.00080.x Microlevelling procedures applied to regional aeromagnetic data: An example from the Transantarctic Mountains Geophysics Fraser 31 1066 1966 10.1190/1.1439840 Some numerical techniques for application in mining exploration Gallagher 1136 1981 A theoretical analysis of the properties of median filters Median filtering: Statistical properties Justusson 1981 Liukkonen 1996 Levelling methods for aerogeophysical data Journal Australian Geology and Geophysics Luyendyk 17 31 1997 Processing of airborne magnetic data Exploration Geophysics Minty 22 591 1991 10.1071/EG991591 Simple micro-levelling for aeromagnetic data Surveys in Geophysics Pedersen 25 151 2004 10.1023/B:GEOP.0000028161.90659.4b Airborne VLF measurements and variations of ground conductivity: A tutorial Exploration Geophysics Reeves 24 115 1993 10.1071/EG993115 Limitations imposed by geomagnetic variations on high quality aeromagnetic surveys 2002 HERZ TOTEM-2A VLF electromagnetic system Geophysics Smith 55 293 1990 10.1190/1.1442837 Gridding with continuous curvature splines in tension Journal of Canadian Society Exploration Geophysicists Stewart 21 54 1985 Median filtering: Review and a new F/K analogue design Urquhart 371 1989 Decorrugation of enhanced magnetic field maps