Design of a weak signal acquisition system for hydrophone arrays

Abstract

To address the challenges of high costs and limited storage capacity for transmitting and storing large datasets in contemporary hydroacoustic sensing systems for marine environmental monitoring, a low-cost, high-precision hydrophone array data acquisition system optimized for weak signal detection has been developed. The central control unit is based on the STM32F429 microcontroller, which operates in a parallel software execution mode to control the AD7606C-16 for signal acquisition during external interrupts. Data is stored in SRAM in a double-buffering mode and processed using a collaborative compression algorithm. This algorithm combines an adaptive differential encoding scheme for the upper 8 bits and an integer u-law encoding scheme for the lower 8 bits. The processed data is subsequently stored on an SD card and uploaded to the host computer via a USB-TTL module. The system achieves a real-time continuous storage rate with eight channels at 120 kSPS per channel. The sector-level data reconstruction test achieved a compression rate of 68.9% and real-time continuous storage with an absolute error of 5.82mv. Testing in an anechoic pool confirmed the system adheres to performance specifications, operates stably and reliably, and demonstrates practical deployment value.