History of aeromagnetic surveying in Canada

Autor:	Peter Hood
Rok vydání:	2007
Předmět:	Magnetometer Rotor (electric) Compressed air Geology Geodesy law.invention Magnetic field Precambrian Geophysics law Shield Prospecting Vertical field Seismology
Zdroj:	The Leading Edge. 26:1384-1392
ISSN:	1938-3789 1070-485X
Popis:	The first instrument to measure the magnetic field while being flown in an aircraft was the Earth inductor magnetometer. This was done in the USSR in 1936. But the system's sensitivity of 100 nT, called gammas in those days, was hardly suitable for routine surveys of large areas. Hans Lundberg built, after World War II, a helicopter-borne system for mineral prospecting in the Canadian Precambrian Shield. The rotor was spun by compressed air at 1800 Hz between a set of gimbal-mounted Helmholtz coils whose axis was aligned vertically. Thus, the system measured variations of the Earth's vertical field with a sensitivity of about 25 nT.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::aaff6a697a52ddc3c3134a5144e1e5b4 https://doi.org/10.1190/1.2805759 Zobrazit plný text záznamu