Depth Dynamics via One-Bit Frequency Probing in Embedded Direct Time-of-Flight Sensing.

Time-of-flight (ToF) sensors with single-photon avalanche diodes (SPADs) estimate depth by accumulating a histogram of photon return times, which discards the timing information required to measure depth dynamics, such as vibrations or transient motions. We introduce a method that transforms a direct ToF sensor into a depth frequency analyzer capable of measuring high-frequency motion and transient events using only lightweight, on-sensor computations. By replacing conventional discrete Fourier transforms (DFTs) with one-bit probing sinusoids generated via oversampled sigma-delta modulation, we enable in-pixel frequency analysis without multipliers or floating-point operations.