Time of flight ranging system and ranging method thereof

A time of flight ranging system, comprising a light source module, a sensing array, a charge accumulation circuit connected to the sensing array, and a processing module, the processing module being configured to perform the following steps:

• perform scattering detection, and obtain a scattering coefficient of each pixel unit in the sensing array, which specifically includes:
• controlling the light source module to emit scattering detection light into a detection field of view, the detection field of view includes detected objects at different distances and is divided into a close-range area and a far-range area;
• obtain a detection value of each pixel unit generated by reflected light and scattered light generated by the reflected light, and calculate a ratio of the detection value generated by each pixel unit to a sum of the detection values generated by all pixel units of the entire sensing array as a corresponding scattering coefficient of the pixel unit;
• perform distance measurement, and obtain an initial measurement value output by each pixel unit;
• correct, according to the scattering coefficients, initial measurement values output by at least part of the pixel units to obtain corrected measurement values;
• calculate corrected measurement distance based on the corrected measurement values;
• wherein the method for obtaining a detection value of each pixel unit generated by reflected light and scattered light generated by the reflected light includes:
• controlling the charge accumulation circuit to accumulate, in a charge accumulation window, electric charges generated by reception of pulses of the scattering detection light by each pixel unit of the sensing array after the pulses are reflected, to obtain the detection value generated by each pixel unit;
• the scattering detection light is pulsed light, and in a single pulse of the scattering detection light, part of the pulse overlaps with the charge accumulation window, and part of the pulse lags behind the charge accumulation window;
• the overlapped width of the pulse of the scattering detection light and the charge accumulation window is t, the distance range of the close-range area is 0˜ct/2, and the distance of the far-range area is greater than ct/2.