| 摘要 |
<p>A method and a system is provided for remote detection of markers (10), each marker comprising at least two magnetic elements (13) arranged in a predetermined relationship providing an identity of the marker, by either exciting a respective magnetic element (13) to resonate mechanically or by exciting an electrical resonant circuit (14), to which the respective magnetic element (13) is coupled, to oscillate electrically. A resonant frequency (fres) of the respective magnetic element or of the electrical resonant circuit depends on an applied magnetic field (H), which is given a varying orientation. A corresponding variation in the resonant frequency (fres) is monitored, and an extreme value (f¿min local?) of the variation is detected. A momentary orientation (α¿min local?) of the magnetic field is determined in response to the detection of the extreme value, and an orientation of the respective element (13) is determined from this momentary field orientation.</p> |
