A frequency modulation continuous wave, FMCW, -based system, comprising: at least one emitter configured to transmit at least one wave of radiation to a scene, wherein the transmitted wave is linearly modulated in a frequency domain, wherein the modulation is subject to impairments causing a non-linearity of the modulation of the transmitted wave in the frequency domain; at least one receiver configured to receive reflections of the transmitted wave from multiple objects located at different locations in the scene; a mixer operatively connected to the emitter and the receiver and configured to interfere a copy of the wave outputted by the emitter with the reflections of the transmitted wave received by the receiver to produce a beat signal with spectrum peaks corresponding to reflections from the different locations at the scene, wherein the beat signal is distorted due to the non-linearity of the modulation; and a processor configured to detect a number of spectrum peaks in the distorted beat signal; characterized in that the processor is further configured to, only in response to detecting multiple spectrum peaks, jointly determine coefficients of a basis function approximating the non-linearity of the modulation and distances to the different locations at the scene having the objects causing the reflections resulting in the spectrum peaks in the distorted beat signal; wherein the processor is configured to approximate the non-linearity of the modulation in the phase domain using a polynomial basis function; wherein the processor is configured to compare the number of spectrum peaks in the distorted beat signal with a threshold defining an accuracy of the distance estimation, and to determine the distances to different locations in the scene only when the number of spectrum peaks in the distorted beat signal is greater than the threshold; and wherein the processor is configured to select an order of the polynomial basis function based on the number of spectrum peaks in the distorted beat signal. at least one emitter configured to transmit at least one wave of radiation to a scene, wherein the transmitted wave is linearly modulated in a frequency domain, wherein the modulation is subject to impairments causing a non-linearity of the modulation of the transmitted wave in the frequency domain; at least one receiver configured to receive reflections of the transmitted wave from multiple objects located at different locations in the scene; a mixer operatively connected to the emitter and the receiver and configured to interfere a copy of the wave outputted by the emitter with the reflections of the transmitted wave received by the receiver to produce a beat signal with spectrum peaks corresponding to reflections from the different locations at the scene, wherein the beat signal is distorted due to the non-linearity of the modulation; and a processor configured to detect a number of spectrum peaks in the distorted beat signal; characterized in that the processor is further configured to, only in response to detecting multiple spectrum peaks, jointly determine coefficients of a basis function approximating the non-linearity of the modulation and distances to the different locations at the scene having the objects causing the reflections resulting in the spectrum peaks in the distorted beat signal; wherein the processor is configured to approximate the non-linearity of the modulation in the phase domain using a polynomial basis function; wherein the processor is configured to compare the number of spectrum peaks in the distorted beat signal with a threshold defining an accuracy of the distance estimation, and to determine the distances to different locations in the scene only when the number of spectrum peaks in the distorted beat signal is greater than the threshold; and wherein the processor is configured to select an order of the polynomial basis function based on the number of spectrum peaks in the distorted beat signal.