Method for detecting an electromagnetic use-signal with a measurement system comprising the following steps: a. Providing an input interface for an electromagnetic input signal which is set up in such a way that an electromagnetic use-signal is provided; b. Providing an electromagnetic reference signal source which is set up in such a way that an electromagnetic reference signal comprising M discrete tones with M ≥ 2 is provided; and c. Providing a subsystem, comprising: i. a first splitting element which is set up in such a way that the use-signal is split into a multitude of N partial use-signals with N ≥ 2; ii. a second splitting element which is set up in such a way that the reference signal is split into a multitude of N partial reference signals, wherein N is the number of corresponding partial use-signals; iii. N corresponding mixing elements which are set up in such a way that each partial use-signal (2511-n) is mixed with the corresponding partial reference signal (2521-n) to generate a total number of ∑ n = 1 N K n partial mixing signals, wherein the n-th mixing element (2530-n) generates K n partial mixing signals (2531-n); iv. a number of ∑ n = 1 N K n corresponding acquisition elements which are set up in such a way that the ∑ n = 1 N K n partial mixing signals are digitized such that ∑ n = 1 N K n digitized partial mixing signals are generated; v. a digital signal processor, that is setup in such a way that a digital use-signal is reconstructed from the digitized partial mixing signals using a transformation based on a system model that relates the ∑ n = 1 N K n digitized partial mixing signals to the use-signal and that comprises at least one model parameter related to at least one of the properties of the measurement system; characterized in that: d. at least one partial reference signal (2521-n) comprises at least two spectral tones, and that e. the totality of all partial mixing signals comprises redundant information that is used to determine the at least one model parameter of the measurement system. a. Providing an input interface for an electromagnetic input signal which is set up in such a way that an electromagnetic use-signal is provided; b. Providing an electromagnetic reference signal source which is set up in such a way that an electromagnetic reference signal comprising M discrete tones with M ≥ 2 is provided; and c. Providing a subsystem, comprising: i. a first splitting element which is set up in such a way that the use-signal is split into a multitude of N partial use-signals with N ≥ 2; ii. a second splitting element which is set up in such a way that the reference signal is split into a multitude of N partial reference signals, wherein N is the number of corresponding partial use-signals; iii. N corresponding mixing elements which are set up in such a way that each partial use-signal (2511-n) is mixed with the corresponding partial reference signal (2521-n) to generate a total number of ∑ n = 1 N K n partial mixing signals, wherein the n-th mixing element (2530-n) generates K n partial mixing signals (2531-n); iv. a number of ∑ n = 1 N K n corresponding acquisition elements which are set up in such a way that the ∑ n = 1 N K n partial mixing signals are digitized such that ∑ n = 1 N K n digitized partial mixing signals are generated; v. a digital signal processor, that is setup in such a way that a digital use-signal is reconstructed from the digitized partial mixing signals using a transformation based on a system model that relates the ∑ n = 1 N K n digitized partial mixing signals to the use-signal and that comprises at least one model parameter related to at least one of the properties of the measurement system; i. a first splitting element which is set up in such a way that the use-signal is split into a multitude of N partial use-signals with N ≥ 2; ii. a second splitting element which is set up in such a way that the reference signal is split into a multitude of N partial reference signals, wherein N is the number of corresponding partial use-signals; iii. N corresponding mixing elements which are set up in such a way that each partial use-signal (2511-n) is mixed with the corresponding partial reference signal (2521-n) to generate a total number of ∑ n = 1 N K n partial mixing signals, wherein the n-th mixing element (2530-n) generates K n partial mixing signals (2531-n); iv. a number of ∑ n = 1 N K n corresponding acquisition elements which are set up in such a way that the ∑ n = 1 N K n partial mixing signals are digitized such that ∑ n = 1 N K n digitized partial mixing signals are generated; v. a digital signal processor, that is setup in such a way that a digital use-signal is reconstructed from the digitized partial mixing signals using a transformation based on a system model that relates the ∑ n = 1 N K n digitized partial mixing signals to the use-signal and that comprises at least one model parameter related to at least one of the properties of the measurement system; d. at least one partial reference signal (2521-n) comprises at least two spectral tones, and that e. the totality of all partial mixing signals comprises redundant information that is used to determine the at least one model parameter of the measurement system.