A method for acquiring a detected light optical signal, the method comprising the steps of: providing (1700, 1702) a light source for illumination of a field of view; an optical detector; an analog-to-digital converter, ADC, with a sample rate of F Hz and B bits of resolution; emitting one pulse from said light source in said field of view; detecting a reflection signal of said pulse by the optical detector; acquiring j points for said reflection signal by said ADC by acquiring one of said j points at each 1 / F second thereby converting said reflection signal into a digital signal waveform of j points; storing, in a buffer, said digital signal waveform of j points; said method being characterized in that it further comprises the steps of: introducing a phase shift of 2π divided by a factor P between said emitting light pulse and a beginning of said acquiring j points by the ADC; repeating, P times, said steps of emitting, detecting, acquiring, storing and introducing a further phase shift of 2π/P between said emitting light pulse and a beginning of said acquiring j points by the ADC, to store, in said buffer, an interleaved waveform of P x j points, said interleaved waveform being equivalent to a single acquisition with a temporal resolution of 1 / (F x P) second; accumulating M traces of interleaved P x j points for a total of N = M x P acquisition sets, N being a total number of pulses emitted; using the N sets, creating one combined trace of the reflected signal by adding each point of the M traces, point per point, to generate one accumulated digital trace of j x P points, each point in the combined trace being an accumulation of M = N / P sets and an effective time resolution of the combined trace being 1 / (F x P) second; wherein a length of said buffer is at least j x P and a number of bits of each element in said buffer is sufficient to prevent overflow; and wherein said sample rate of said ADC is virtually increased thereby allowing a low cost ADC having a low sample rate F to be used. providing (1700, 1702) a light source for illumination of a field of view; an optical detector; an analog-to-digital converter, ADC, with a sample rate of F Hz and B bits of resolution; a light source for illumination of a field of view; an optical detector; an analog-to-digital converter, ADC, with a sample rate of F Hz and B bits of resolution; emitting one pulse from said light source in said field of view; detecting a reflection signal of said pulse by the optical detector; acquiring j points for said reflection signal by said ADC by acquiring one of said j points at each 1 / F second thereby converting said reflection signal into a digital signal waveform of j points; storing, in a buffer, said digital signal waveform of j points; said method being characterized in that it further comprises the steps of: introducing a phase shift of 2π divided by a factor P between said emitting light pulse and a beginning of said acquiring j points by the ADC; repeating, P times, said steps of emitting, detecting, acquiring, storing and introducing a further phase shift of 2π/P between said emitting light pulse and a beginning of said acquiring j points by the ADC, to store, in said buffer, an interleaved waveform of P x j points, said interleaved waveform being equivalent to a single acquisition with a temporal resolution of 1 / (F x P) second; accumulating M traces of interleaved P x j points for a total of N = M x P acquisition sets, N being a total number of pulses emitted; using the N sets, creating one combined trace of the reflected signal by adding each point of the M traces, point per point, to generate one accumulated digital trace of j x P points, each point in the combined trace being an accumulation of M = N / P sets and an effective time resolution of the combined trace being 1 / (F x P) second; wherein a length of said buffer is at least j x P and a number of bits of each element in said buffer is sufficient to prevent overflow; and wherein said sample rate of said ADC is virtually increased thereby allowing a low cost ADC having a low sample rate F to be used. introducing a phase shift of 2π divided by a factor P between said emitting light pulse and a beginning of said acquiring j points by the ADC; repeating, P times, said steps of emitting, detecting, acquiring, storing and introducing a further phase shift of 2π/P between said emitting light pulse and a beginning of said acquiring j points by the ADC, to store, in said buffer, an interleaved waveform of P x j points, said interleaved waveform being equivalent to a single acquisition with a temporal resolution of 1 / (F x P) second; accumulating M traces of interleaved P x j points for a total of N = M x P acquisition sets, N being a total number of pulses emitted; using the N sets, creating one combined trace of the reflected signal by adding each point of the M traces, point per point, to generate one accumulated digital trace of j x P points, each point in the combined trace being an accumulation of M = N / P sets and an effective time resolution of the combined trace being 1 / (F x P) second; wherein a length of said buffer is at least j x P and a number of bits of each element in said buffer is sufficient to prevent overflow; and wherein said sample rate of said ADC is virtually increased thereby allowing a low cost ADC having a low sample rate F to be used.