Patent ID: 6972712

Claim:
A method for processing a time domain reflectometry (TDR) signal used to determine at least one process variable for a material in a tank, wherein said TDR signal has been generated by a radar level gauge system comprising a pulse generator, a probe extending into the tank for guiding the pulse, and a receiver for receiving said TDR signal, and wherein the TDR signal comprises at least a surface reflection pulse caused by an interface between different materials in the tank, and an interfering pulse caused by a transition between the pulse generator and the probe, said method comprising: obtaining a first sampled TDR signal with an amplification such that the interfering pulse is unsaturated, determining a compensation pulse signal using a previously stored pulse shape and a current pulse position, subtracting said compensation pulse signal from the first sampled TDR signal, determining if a surface reflection occurs in a zone where said interfering pulse has a significant interfering effect on any surface reflection pulse occurring in this zone, and if no surface reflection occurs in this zone, updating the current pulse position.