High-Precision Joint Ranging Method Based on Pseudo-Random Code and Single-Tone Signal

In this paper, a laser joint ranging method, which integrates the pseudo-random code with the single-tone signal, is proposed for realizing high accuracy and precision. The single-tone signal utilizes a phase-shift method for high-precision ranging, while the pseudo-random code is employed to solve the distance ambiguity problem in the phase-shift method. The merging of the pseudo-random code with the single-tone signal in the digital domain and the data processing in the digital domain achieve simultaneous modulation and simultaneous ranging, which ensures the complete synchronization of the two signals during both transmission and processing. Furthermore, the pseudo-random code is band-limited, which ensures that the pseudo-random code signal and the single-tone signal do not overlap spectrally, thus preventing interference between them. The experimental results indicate that the ranging accuracy is 59.84 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\bf \mu m}$</tex-math></inline-formula> and the ranging precision is 14.72 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\bf \mu m}$</tex-math></inline-formula>. Finally, the article analyzes the selection principles of single-tone signal and pseudo-random code, providing a reference for the selection of single-tone signal and pseudo-random code in this joint ranging method.