摘要 |
<p>A method of guiding a probe (20) to a target includes placing a magnetic field generator at the target and guiding the probe (20) to a region of the target. The probe carries a survey sensor pack (28) and the method includes using the survey sensor pack (28), firstly, to obtain a plurality of survey readings and, secondly, to obtain a plurality of magnetic beacon readings using a magnetic field generated by the magnetic field generator. A selected number of the survey readings and the magnetic beacon readings are compared and a difference between the survey readings and the magnetic beacon readings is determined. The method includes compensating for that difference thereafter to guide the probe (20) to the target.</p> |