A Low-Cost Full-Spectrum Acquisition Method Based on Compressed Sensing and its Application in Wastewater Detection

Full-spectrum detection (FSD) is widely used in wastewater treatment processes (WWTPs) due to its higher resistance to interference compared to single-wavelength detection. However, acquiring full-spectrum typically involves precision and expensive equipment, which significantly raises detection costs. This article proposes a low-cost full-spectrum acquisition method (LFAM) based on compressed sensing (CS) to eliminate the reliance on high-cost hardware in spectral acquisition. It replaces the expensive light source and spectrometer with a self-made laser and a photovoltaic cell, and designs a corresponding implementation system. Subsequently, a new CS model is introduced to ensure accurate spectral signal observation under the low-cost condition. Moreover, a low-cost measurement framework for photovoltaic cell spectral response curve is proposed, incorporating three innovative algorithms for curve fitting, error compensation, and coefficient fusion, thus circumventing the need for specialized measurement equipment. Additionally, three objectives are designed to optimize the observation matrix, with the goal of minimizing system modeling and signal reconstruction errors. Experimental findings demonstrate that LFAM can indirectly obtain the spectra of similar quality to those acquired by spectrometers, with an accuracy exceeding 90%, while reducing costs by nearly a hundredfold, opening up a new era of development in the field of FSD.