Research on nanometer displacement telemetry based on digital zero intermediate frequency

A small volume, light weight, portable laser Doppler nanometer displacement telemetry system was presented that meet the demand of nanometer detection for the ultra-stable platform in the aerospace industry. In the electrical module, the system adopted the demodulation scheme based on digital zero intermediate frequency, thus the decrease of the analog devices was helpful to improve the detection resolution and precision of the system. Digital zero intermediate frequency demodulation method for the nanoscale vibration amplitude was analyzed theoretically and implemented. The proof experiment shows that the minimum phase of 1, equal to vibration amplitude 2.15 nm detectable capacity is achieved. PI-E501 standard vibration source, placed at 10 meter distance from the system, was employed to testify the performance of the laser Doppler nanometer displacement telemetry system and telemetry with amplitudes of 1000, 200, 10 nm at the frequency 10 Hz and 1000 Hz was achieved. This system performance verification experiment shows that the laser Doppler nanometer displacement telemetry system achieve the ability of dozens of herts to hundred herts frequency, microns or even smaller vibration amplitude detection for the ultra-stable platform in the aerospace industry.