Signal Processing in Solid-State Coherent Lidar Using LabVIEW

Measurement of speed of moving object by a solid-state coherent lidar is studied. An injection seeding Nd∶YAG pulse laser is used as the transmitter. The reflected signal and referenced signal are combined via a single mode fiber coupler, the output heterodyne signal from the fiber coupler is detected by a photo detector and sampled by a digital oscilloscope. LabVIEW is applied to build up the interface between the oscilloscope and PC. Resolution of the measured frequency shift is improved using zoom fast Fourier transform(ZFFT) so that the resolution of measurement of speed is improved.