MULTI-FREQUENCY BORING TOOL LOCATING SYSTEM AND METHOD

摘要

Arrangements, apparatus and associated methods are described for use in a multi-frequency boring tool locating system. The boring tool includes a transmitter for transmitting a locating signal at two or more selectable frequencies. One set of above ground procedures may be applied to the transmitter in order to change the frequency of the boring tool transmitter. Another set of procedures is applicable for changing the frequency during below ground drilling operations, for example, by subjecting the boring tool to a predetermined roll orientation sequence. An enhanced portable locator operates in a manual or automatic mode to receive locating frequency information transmitted from the boring tool transmitter including frequency updates. Boring tool transmitter, as well as above ground locator shutdown/restart procedures are described relating to multi-frequency operation. A tone detector is described which implements one or more digital match filters.

主权项

1. A transmitter for use in an inground tool as part of a system in which the inground tool is moved underground in a region, said transmitter comprising:
a transmitter section for transmitting a locating signal from the boring tool for use in tracking an underground position of the boring tool in said region, the locating signal characterized by a transmission frequency; a sensor for detecting a roll orientation of the transmitter; and a processor for monitoring the detected roll orientation to identify a roll orientation pattern including at least one roll orientation at which the transmitter is held stationary for a predetermined period of time and for changing the transmission frequency responsive to detecting the roll orientation pattern.