Application for Patent of RICHARD R. ERNST for TWO DIMENSIONAL GYROMAGNETIC RESONANCE SPECTROSCOPY The multiplet spectral structure produced by coupled gyromagnetic resonators, such as heteronuclear coupling, is resolved by inducing a train of transient free induction decay (RID) resonances of a first group of gyromagnetic bodies, such as carbon-13 nuclei coupled to a second group of gyromagnetic bodies, such as protons, and detecting the FID resonance. A decoupling r.f. magnetic field is applied to the second group during free induction decay resonance of the first group for decoupling the spins of the first and second groups during detection of resonance of the first group. The duration of the decoupling effect is changed from one successive free induction decay resonance to the next and the detected resonance data is stored as a function of the change in the decoupling effect. The detected resonance data which is a function of two time intervals is then double Fourier transformed into the frequency doma
