All-orientation detection in underground mines can be implemented by uncoplanarity coaxial off-set loops,coplanarity coaxial off-set loops,or central loops in PROTEM-47 system made in Canada.

• 采用加拿大产PROTEM-47瞬变电磁系统,通过不共面同轴偶极方式、共面偶极方式或者中心方式布置线圈实现了井下全方位探查。