A Real-Time Data Acquisition System for Single-Band Bathymetric LiDAR

Bathymetric light detection and ranging (LiDAR), which uses a laser with narrow pulsewidth and a high repetition rate, requires a real-time data acquisition system (RTDAQS) for quickly transmitting data with the characteristic of high sampling rates, high resolution, and high accuracy. However, none of the RTDAQS in the world has reached these requirements. For this reason, this article presents an RTDAQS with high-speed serializer-deserializer (SerDes) data transfer technology based on the architecture of analog-to-digital converter (ADC) + field-programmable gate array (FPGA) + ZYNQ. This RTDAQS consists of an acquisition board and a storage board. The acquisition board integrates the high-speed ADC acquisition module, the input/output (I/O) control module, the data transmission module, and the FPGA chip module. The storage board integrates the FPGA Mezzanine Card (FMC) interface, solid state, and ZYNQ chips. The corresponding software includes configuration for the high-speed ADC acquisition module, the I/O control module, the data transmission module, and the FMC interface module. The RTDAQS, which is embedded in the LiDAR with a laser pulsewidth of 2.5 ± 0.2 ns and a frequency of 500 Hz, has been verified by the experiments in the indoor sink, outdoor pond, river, reservoir, and the Beihai Bay of the Pacific Ocean. The experimental results and comparison experiments demonstrate that the presented RTDAQS can reach a sampling rate of 2 GS/s and a sampling resolution of 14 bits and a sampling accuracy of 6 LSB with an acquisition error within 0.1 m, which meets the demands of a high sampling rate with high accuracy data acquisition and quick data transmission in practice, and can be applied to various devices.