An imaging method carried out by a coherent lidar, comprising the steps of: - A generating a signal called a local oscillator which has a local oscillator frequency f OL which is periodically modulated and which is constituted by the total of a mean value f0 and a periodic modulation frequency f modOL, each period comprising P linear portions which have P frequency gradients α OLj which are indexed j, j varying from 1 to P, - B generating, from the local oscillator, N emission signals Si which are indexed i, i varying from 1 to N, each emission signal Si having an emitted frequency f mod,i which has P predetermined frequency gradients α i,j which are synchronised with the P local oscillator frequency gradients, and - C emitting each emission signal Si in an associated direction (Θi), the directions being selected so as to cover a predetermined portion of space corresponding to the observed field, each direction corresponding to a pixel Ai of an image of the field, - D collecting N backscattered signals which are output from the backscattering of the N emission signals, respectively, by at least one element which is present in the portion of space, a backscattered signal which is indexed i having a signal frequency f s,i, - E detecting a beat signal Sb which is generated from the interference between the local oscillator and the N backscattered signals, - F modulating in a complex manner the beat signal Sb by the modulation frequency of the local oscillator f modOL, - G carrying out NxP complex demodulations of the modulated beat signal, each complex demodulation which is indexed i, j involving demodulating by a demodulation frequency f demodi,j having a unique gradient which is equal to the gradient α i,j in order to obtain NxP demodulated signals S demodi,j. - H determining NxP spectral power densities SP i,j of the NxP demodulated signals Sdemodij, - I determining characteristic frequencies (vij) corresponding to local maxima of the NxP spectral power densities, - J determining, for each pixel Ai, at least one speed information item (vi) and at least one distance information item (di) from the characteristic frequencies (vij). - A generating a signal called a local oscillator which has a local oscillator frequency f OL which is periodically modulated and which is constituted by the total of a mean value f0 and a periodic modulation frequency f modOL, each period comprising P linear portions which have P frequency gradients α OLj which are indexed j, j varying from 1 to P, - B generating, from the local oscillator, N emission signals Si which are indexed i, i varying from 1 to N, each emission signal Si having an emitted frequency f mod,i which has P predetermined frequency gradients α i,j which are synchronised with the P local oscillator frequency gradients, and - C emitting each emission signal Si in an associated direction (Θi), the directions being selected so as to cover a predetermined portion of space corresponding to the observed field, each direction corresponding to a pixel Ai of an image of the field, - D collecting N backscattered signals which are output from the backscattering of the N emission signals, respectively, by at least one element which is present in the portion of space, a backscattered signal which is indexed i having a signal frequency f s,i, - E detecting a beat signal Sb which is generated from the interference between the local oscillator and the N backscattered signals, - F modulating in a complex manner the beat signal Sb by the modulation frequency of the local oscillator f modOL, - G carrying out NxP complex demodulations of the modulated beat signal, each complex demodulation which is indexed i, j involving demodulating by a demodulation frequency f demodi,j having a unique gradient which is equal to the gradient α i,j in order to obtain NxP demodulated signals S demodi,j. - H determining NxP spectral power densities SP i,j of the NxP demodulated signals Sdemodij, - I determining characteristic frequencies (vij) corresponding to local maxima of the NxP spectral power densities, - J determining, for each pixel Ai, at least one speed information item (vi) and at least one distance information item (di) from the characteristic frequencies (vij).