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TitreModelling the disturbance caused by a dc-electrified railway to geomagnetic measurements
AuteurPirjola, R; Newitt, L; Boteler, D; Trichtchenko, L; Fernberg, P; McKee, L; Danskin, D; Jansen van Beek, G
SourceEarth, Planets and Space vol. 59, 2007 p. 943-949, (Accès ouvert)
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100352
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetsgéomagnétisme; champs géomagnétiques; variations géomagnétiques; modèles; géophysique
Illustrationsgraphs; tables
ProgrammeTargeted Hazard Assessments in Northern Canada, Géoscience pour la sécurité publique
Diffusé2007 08 31
Résumé(disponible en anglais seulement)
Magnetic fields created by a dc-electrified railway are a nuisance to the operation of a geomagnetic observatory and also disturb other electromagnetic studies. Theoretical formulas that enable quantitative estimates of the magnetic effect of a dc railway including leakage currents in the ground are presented in this paper. They are illustrated by numerical examples. The validity of the theoretical model was verified by measurements carried out in the vicinity of a nearly north-south railway in Calgary, Canada. The earth structure in that area is approximately layered, which is an assumption included in the theoretical model. The agreement between the measured magnetic fields due to trains and the theoretical values is good. Numerical computations indicate that magnetic fields larger than the maximum allowable noise level (assumed to be about 10 pT) at today's magnetic observatories may extend to distances of tens of kilometres from a railway. We have prepared computer programs based on the theoretical formulas in the MatLab, Octave, FORTRAN and IDL languages, in which the locations (i.e. the latitudes and the longitudes) of the point of observation, of the feeding substations and of the trains, together with the feeding and leakage currents and the heights of the feeding lines, can be given as inputs. Key words: Magnetic observatory, dc train, leakage current, dc magnetic field.