MULTI-STAGE EQUALISATION METHOD AND APPARATUS FOR USE IN TELEMETRY

摘要

The present invention relates to inspection apparatus for use in wellbores in the oil and gas industries. In particular the invention relates in general to the field of transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides a method and apparatus for determining analogue filter parameters for an analogue front end comprising a plurality of filter stages receiving signals from a telemetry module, by repeating the steps of;receiving a signal of a known frequency and processing said signal by determining the magnitude of the frequency of the received signal until a plurality of signals have been received and processed;calculating an optimum set of filter parameters in dependence upon the measured frequency magnitudes and a predefined set of filter stage frequency responses..