A version of the solution of the problem of simultaneous determination of the structure and characteristics of a two- dimensional signal and two-dimensional complex transfer or instrumental functions is considered. The solution is based on measurements of four independent intensity distributions for spectral representation of a signal: Isr((omega) x, (omega) y) for a signal subjected to the transfer function, Ismr((omega) x, (omega) y) for a signal affected by additional specially produced modulation and the transfer function, Isrn((omega) x, (omega) y) for a signal of the form Isr((omega) x, (omega) y) with a certain additional modulation at thy output, and Ismrn((omega) x, (omega) y) for a signal of the form Ismr((omega) x, (omega) y) with a certain modulation at the output. The intensity distributions obtained in the work make it possible to calculate the amplitude and phase components of the signal being analyzed and the transfer function. Additional modulations should provide visualization of phase information in one form or another. Linear amplitude modulation, which represents a particular form of spatial modulation, is analyzed. For this case, concrete expressions making it possible to calculate the amplitude and phase characteristics of the spectra of the signal being analy and the transfer function and, therefore, the characteristics of both the signal itself and the transfer function are obtained.