Signal correction method, system for correcting a measured signal, as well as oscilloscope

1. A signal correction method for correcting a measured signal having the following steps:

processing a digital representation of a first signal at a first measurement input;

processing a digital representation of a second signal at a second measurement input corresponding to the first signal convoluted with a transfer function;

determining the transfer function for correcting the measured signal;

applying a signal to be measured to the second measurement input yielding a digital representation of a third signal at the second measurement input;

applying a signal causing interference to the first measurement input yielding a digital representation of the signal causing interference; and

correcting the digital representation of the third signal by using a convolution of the digital representation of the signal causing interference and the transfer function to obtain the corrected measured signal.

2. The method according to claim 1 , wherein the first signal is created by applying the signal causing interference to the first measurement input.

3. The method according to claim 1 , wherein the signal causing interference is an interfering signal that interferes with the signal to be measured.

4. The method according to claim 1 , wherein the third signal comprises the signal to be measured and interference caused by the signal causing interference.

5. The method according to claim 1 , wherein the second signal is a portion of the third signal.

6. The method according to claim 1 , wherein the third signal is corrected in real-time, in particular by determining the transfer function in real-time.

7. The method according to claim 1 , wherein the first measurement input and the second measurement input are coherent.

8. The method according to claim 1 , wherein first signal is a periodic signal.

9. The method according to claim 1 , wherein the amplitude of first signal is at least one order of magnitude larger than the amplitude of the signal to be measured.

10. The method according to claim 1 , wherein the first signal applied to the first measurement input is a calibrating signal and that the second signal is a voltage measured using a short-circuited differential probe.

11. The method according to claim 1 used for eliminating common-mode interference of a measured signal.

12. A system for correcting a measured signal, comprising a first measurement input, a second measurement input, a control unit, and an analog to digital converter allocated to each of the measurement inputs, wherein the control unit is configured to:

process a digital representation of a first signal at a first measurement input;

process a digital representation of a second signal at a second measurement input corresponding to the first signal convoluted with a transfer function;

determine the transfer function for correcting the measured signal;

apply a signal to be measured to the second measurement input yielding a digital representation of a third signal at the second measurement input;

apply a signal causing interference to the first measurement input yielding a digital representation of the signal causing interference; and

correct the digital representation of the third signal by using a convolution of the digital representation of the signal causing interference and the transfer function to obtain the corrected measured signal.

13. An oscilloscope having a system for correcting a measured signal, comprising a first measurement input, a second measurement input, a control unit, an analog to digital converter allocated to each of the measurement inputs, wherein the control unit is configured to:

process a digital representation of a first signal at a first measurement input;

process a digital representation of a second signal at a second measurement input corresponding to the first signal convoluted with a transfer function;

determine the transfer function for correcting the measured signal;

apply a signal to be measured to the second measurement input yielding a digital representation of a third signal at the second measurement input;

apply a signal causing interference to the first measurement input yielding a digital representation of the signal causing interference; and

correct the digital representation of the third signal by using a convolution of the digital representation of the signal causing interference and the transfer function to obtain the corrected measured signal.