Patent ID: 8310655

Claim:
A method for acquiring a detected light optical signal and generating an accumulated digital trace, the method comprising: providing 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; 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, to store, in said buffer, an interleaved waveform of P×j points, said interleaved waveform being equivalent to a single acquisition with a temporal resolution of 1/(F×P) second; accumulating M traces of interleaved P×j points for a total of N=M×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×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×P) second; wherein a length of said buffer is at least j×P and a number of bits of each element in said buffer is B+log 2 M; 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.