1. Method for determining parasitization situations due to spectral aliasing in a wideband digital receiver, the method being implemented by means of an interferometer with P antennas, P being an integer greater than or equal to 1, each antenna being followed by an analog reception channel and at least one digital reception module, the number of digital reception modules being R, the method comprising at least one step of:
- sampling of the signals delivered by the set of reception chains, using M different
fe sampling frequencies ' m below the Nyquist-Shannon frequency, m ranging from 1 to M,
and M being an integer greater than or equal to 4; the number of digital reception modules operating with a frequency fm being equal to Rm' and the number of digital reception
frequencies providing whole numbers of m samples over a given time AT,
- spectral analysis by successive discrete and synchronous Fourier transforms, allowing, on each of the R digital reception modules, a time/frequency representation called a grid, of temporal resolution AT, and of frequency resolution AF, each element of the grid being called a time/frequency box and containing a complex quantity called a measurement,
- selection of a set of time/frequency domains (in the reception band), each time/frequency domain being perceived in the R digital reception modules as R stackable windows, each of the windows being composed of L associated time/frequency boxes,
- for each time/frequency domain, concatenation of the measurements taken from each of the R windows in the form of R dimension vectors Lx1 denoted W where p is the sensor index and m is the sampling index,
- determination of the presence of possible parasites on each time/frequency domain, consisting in determining among the following hypotheses, from the vectors of measurements obtained, the hypothesis maximizing an approximation of the probability log-density of the R measurement vectors YP™.:
•Ho: absence of parasite,
'Hm„: presence of at least one parasite on sampling m°' with m° e L1 and at least one parasite on

2. Method for determining the parasitization situation according to claim 1, wherein
among the three following hypotheses:
• Ho "no parasite" hypothesis,
• Hi: hypothesis maximizing an approximation of the probability log-density, among the hypotheses at a parasitized sampling frequency,
• Hl : hypothesis maximizing an approximation of the probability log-density
among the hypotheses with two parasitized sampling frequencies,
the chosen hypothesis is:
• Ho if its approximate log-density is that whose adequacy to its supposed
Gaussian law is maximum,
• otherwise H> if its approximate log-density restricted to non-parasitized pathways is that whose adequacy to its supposed Gaussian law is maximum,
• otherwise Hl if its approximate log-density restricted to non-parasitized pathways is that whose adequacy to its supposed Gaussian law is maximum,
otherwise, it is determined whether there are more than two sampling frequencies that are parasitized.
3. Method for determining the parasitization situation according to claim 1 or 2,
wherein at least one of the following criteria is calculated:
- a non-variability criterion of YPm with respect to their filtered value on the different sampling frequencies specific to the antenna p
- an equality criterion of the filtered modules of YPm on the different sampling frequencies specific to the antenna p, and
- a co-linearity criterion of the YP™ filtered on the different sampling frequencies of the antenna p.

4. Method for determining the interference situation according to claim 3, wherein the one or more calculated criteria are used to obtain an approximation of the probability log-density of the measurements.
5. Method for determining the parasitization situation according to any one of claims 1 to 4, wherein the approximate probability log-density is calculated according to the following approximations: for the hypothesis Ho:

• ZP is the average of the vectors Yp™ on the reception modules associated with the
where C is an unknown constant representing the mean power of the parasitization on an axis, and
• Q»m° is the number of p antenna receiving modules, which do not work with the

unknown constant representing the mean power of the parasitization on an axis, and where
~ 1 R s N
Km0,m1 jS t|-,e number of reception modules operating with frequency fem0 or frequency
fp fem .
do not operate with either the sampling frequency yCrno- or the sampling frequency
6. Method for determining the parasitization situation according to claim 1, wherein on each digital reception module, a step of spectral analysis by successive discrete and
N synchronous Fourier transforms, on all the digital reception modules, of the m samples.
provided by the frequency sampling fem during possibly overlapping time intervals AT
makes it possible to obtain, on each of the R digital reception modules, a time/frequency
representation called a grid, of temporal resolution AT common to all the digital reception
modules, and frequency resolution AF common to all digital reception modules, each
element of the grid being called a time/frequency box and containing a complex quantity
called a measurement.

7. Method for determining parasitization situations according to claim 1, wherein a step obtains, possibly off-line, the matching of the frequencies in the reception band at the resolution AF with the frequencies of the Nyquist band of each of the R digital reception modules.
8. Method for determining parasitization situations according to claim 1, wherein the selection of the time/frequency domains is obtained by a division of the time/frequency space into a set of possibly overlapping time/frequency domains.
9. Computer program product comprising a readable information carrier, on which is stored a computer program including program instructions, the computer program being loadable on a data processing unit and designed to cause the implementation of a method according to any one of claims 1 to 8 when the computer program is implemented on the data processing unit.

10. Readable information carrier on which is stored a computer program including program instructions, the computer program being loadable on a data processing unit any one of claims 1 to 8 when the computer program is implemented on the data processing unit.
11. Interferometer with P antennas, P being an integer greater than or equal to 1, each antenna being followed by an analog reception channel and one or more digital reception modules, each digital reception module comprising an analog-to-digital conversion system, a digital processing module, each analog-to-digital conversion system being associated with a respective sampling frequency, an analog-to-digital converter system being associated with a sampling frequency when the analog-to-digital conversion system is able to sample at the sampling frequency, each frequency being such that the sampling carried out by the analog-to-digital conversion system is sampling that does not comply with the Shannon criterion and wherein the interferometer is able to implement a method according to any of the claims 1 to 8.