Research On Marine Detecting Laser Fluorescence Spectrometer Based On DSP

The ocean is a treasury resource for human survival and development, posing far-reaching impacts on promoting national economic development and social progression. The problem of environmental protection is more and more valued by the state and the government.For monitoring marine environment, laser-induced fluorescence techniques can be adopted to rapidly and precisely capture fluorescence information of matters, including colored dissolved organic matters, chlorophyll of oil spill contaminated areas and red tide areas and others.With the development of science and technology, intelligent instrumentation, automation, and miniaturization have become the trend of development. Spectrometers currently used for marine exploration are mostly large in size and complex to operate, not appropriate for the field of rapid detection. Therefore, a portable laser fluorescence spectrometer scheme is proposed in this study. The main system is constituted by area CCD spectral image acquisition and DSP as the core system control and coordination. The design is divided into two parts, hardware and software.The design of the hardware mainly includes power management, video input decoding, liquid-crystal display, data storage and laser control parts, and the device selections of which are conducted via comparison for every part. Application circuits are designed on the basis of manuals and data to coordinate and unify the DSP core party with five hardware parts as an entirety; in addition, Altium Designer is applied to design printed-circuit board, and hardware parts are successfully arranged on a 14×8cm applied board.For software parts, starts from thedevelopment of DSP and construction of simulation environment, application of CCS software and XDS100V2 emulator is introduced. Configurations of attached document necessary for operation of DSP program and configurations of chip-support-library functions are described in detail, and functions are explained from three parts, the video decoding flow, the main function flow and the data storage flow. After completing functions of the system, a programming unit is burned to consolidate the program in FLASH and the design of software part is completed. Finally, spectrum collection and data processing under a resolution of 720×576 as well as displaying in a velocity of 12~16 frames are realized.At the last stage, the experimental system is assembled and an aluminum box of 15cm×10.5cm×5.5cm is taken as the shell of the spectrophotometer. Before the experiment, high-pressure mercury lamp has been used to calibrate the system for its spectrum and determine a measurement range of 411~768nm wavelength. The detailed procedure of the system is described next. Then, seawater samplings, collected from JINHAITAN International Bathing Beach in Weihai, including pure seawater, green seawater, floating algae-contained seawater and engine oil-contained seawater are tested respectively. Existences of chlorophyll and oils are successfully detected and expected functions are basically achieved.