CN-121977515-A - Synchronous measurement system and method for sea water surface temperature and salinity

CN121977515ACN 121977515 ACN121977515 ACN 121977515ACN-121977515-A

Abstract

The invention relates to the technical field of marine environment monitoring and optical sensing, and discloses a sea water surface temperature and salinity synchronous measurement system and a sea water surface temperature and salinity synchronous measurement method. The system comprises a light source module, an optical sensing module, a light field sampling module and a data processing module, wherein the optical sensing module is arranged on the surface layer of the sea water and is in direct contact with a sea water medium, an output light field with statistical characteristics is formed under the interaction of light and the sea water, the light field sampling module is used for sampling the intensity distribution of the output light field to obtain light field statistical data, the data processing module is used for constructing a probability model of the light field intensity distribution based on the light field statistical data, extracting statistical entropy characteristic quantity representing the integral statistical state of the output light field, and inverting the statistical entropy characteristic quantity with the response relation of the sea water temperature and salinity change to obtain the sea water surface layer temperature and salinity. The invention takes the integral statistical state of the light field as a perception core, has the advantages of strong environmental disturbance resistance, universal structure, easy platform integration and the like, and is suitable for long-term in-situ monitoring of platforms such as ocean buoys, floating balls and the like.

Inventors

SUN PENG
ZHAO QIANG
LI YUNZHOU
LIU HAO
HAO ZENGZHOU
HUANG HAIQING
WANG JUNCHENG
PAN DELU

Assignees

山东省科学院海洋仪器仪表研究所

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. A seawater surface temperature and salinity synchronous measurement system, comprising: the light source module is used for generating an incident light signal; the optical sensing module is arranged on the surface layer of the seawater and is in direct contact with the seawater medium, and is used for forming an output light field with statistical characteristics under the interaction of light and the seawater medium; The light field sampling module is used for sampling the intensity distribution of the output light field to obtain light field statistical data; The data processing module is used for constructing a probability model of light field intensity distribution based on the light field statistical data, extracting statistical entropy characteristic quantity representing the overall statistical state of the output light field, and inverting to obtain the sea water surface temperature and the salinity by utilizing the response relation of the statistical entropy characteristic quantity along with the sea water temperature and the salinity.
2. The system of claim 1, wherein the optical sensing module is a multimode optical fiber, and an end face of the multimode optical fiber is in direct contact with seawater, or a side wall of the multimode optical fiber forms a sensitive area in contact with seawater by locally removing or thinning a cladding layer, so as to excite multiple propagation modes and form a random interference light field.
3. The system of claim 1, wherein the optical sensing module comprises a micro-nano scattering structure disposed on an end face of the optical fiber, a surface of the transparent substrate, or a surface of the integrated optical chip, and in direct contact with the seawater medium, for multipath scattering of the incident optical signal to form a scattered light field.
4. The system of claim 1, wherein the light field sampling module is a linear or area array detector disposed within a dry cavity isolated from seawater, and the output light field is transmitted to the light field sampling module through a transparent viewing window or a return light path.
5. The system according to claim 1, wherein the system is integrated in a marine buoy platform or a floating ball platform, wherein the buoy platform is provided with a through installation notch or a guide channel when integrated in the marine buoy platform, the optical sensing module is installed in the notch or the guide channel through an installation frame connected with a buoyancy adjusting device so as to keep the optical sensing module within a preset depth range relative to the instantaneous sea surface, and the floating ball platform is integrally floated on the sea surface when integrated in the floating ball platform, and an optical sensing window is arranged below a shell of the floating ball platform, and the optical sensing module is installed at the optical sensing window so as to be in direct contact with the sea surface.
6. A method for synchronously measuring the temperature and the salinity of a sea water surface layer by adopting the measuring system as claimed in claim 1, which is characterized by comprising the following steps: (1) Coupling an incident optical signal to an optical sensing structure which is arranged on the surface layer of the seawater and is in direct contact with a seawater medium, so that the optical signal forms an output light field with statistical characteristics under the combined action of the optical sensing structure and the seawater medium; (2) Sampling the intensity distribution of the output light field to obtain light field statistical data; (3) Constructing a probability model of light field intensity distribution based on the light field statistical data, and extracting statistical entropy characteristic quantity representing the overall statistical state of the output light field; (4) And inverting to obtain the temperature and the salinity of the sea water surface layer by utilizing the response relation of the statistical entropy characteristic quantity along with the change of the sea water temperature and the salinity.
7. The method according to claim 6, wherein the statistical entropy feature quantity is shannon entropy, relative entropy, conditional entropy, renyi entropy or equivalent statistical entropy form based on light field intensity probability distribution, or a combination of the above various entropy features.
8. The method of claim 6, wherein the optical sensing structure is a multimode optical fiber or an optical sensing structure comprising a micro-nano scattering structure for forming a random interference light field, the micro-nano scattering structure for forming a multipath scattering light field.
9. The method of claim 6, wherein the intensity distribution of the output light field is spatially sampled, time sampled, or a combination thereof, and the light field statistics are single frame spatial intensity distribution data, multi-frame time series intensity distribution data, or a combination thereof.
10. The method of claim 6, wherein the inversion process is implemented based on a pre-established calibration model, a physical-statistical joint model, or a machine learning model, and the seawater temperature and salinity are synchronously inverted by the same statistical entropy feature quantity or the same set of statistical entropy feature quantities.

Description

Synchronous measurement system and method for sea water surface temperature and salinity Technical Field The invention relates to the technical field of marine environment monitoring and optical sensing, in particular to a sea water surface temperature and salinity synchronous measurement system and a sea water surface temperature and salinity synchronous measurement method. Background The temperature and salinity (Pi Wenpi salts) of the sea surface layer are important basic parameters for representing sea-gas interaction, sea mixing process and substance transportation, and the long-term in-situ monitoring has important significance for sea environment research. The existing sea water temperature and salt measurement method mainly comprises a conductivity-temperature (CT) measurement method, a spectral refractive index measurement method and a multi-parameter combination measurement method based on optical fiber sensing. However, the above method has the following disadvantages in practical application: First, temperature and salinity generally depend on different sensitive structures or different measurement channels, the system structure is complex, long-term stability and consistency are poor, and synchronous and high-robustness measurement of temperature and salt parameters is difficult to realize in a single optical channel. Secondly, the existing optical measurement method is mostly based on single optical parameters (such as resonance wavelength drift, reflectivity change, critical angle change or specific scattering angle intensity) for demodulation, and the method is basically dependent on optical characteristics with limited dimensions, is sensitive to light source power fluctuation, structure aging, optical fiber microbending and environmental disturbance, and is easy to generate signal drift or sensitivity degradation in a complex marine environment. Thirdly, under a complex ocean environment, the optical response often presents obvious nonlinear and multiparameter coupling characteristics, the traditional analysis or experience model is difficult to consider measurement accuracy and robustness, and the coupling effect of different environmental parameters on the same optical characteristic is difficult to effectively distinguish. Fourth, even in measurement schemes employing scattering-type or multi-mode interference-type structures, existing methods often still characterize environmental parameters by monitoring certain local intensities, limited statistical features, or specific interference fringe changes, and it is difficult to comprehensively reflect the overall statistical state changes formed during the interaction of the light field and the seawater medium, resulting in limited stability and reliability of measurement results. Therefore, a novel sensing mechanism which does not depend on a single optical parameter and can represent the state change of a light field from an overall level is needed, so that the synchronous and stable measurement of the temperature and the salinity of the sea water surface layer in a single measurement channel is realized, and the novel sensing mechanism has the characteristics of strong environment disturbance resistance, simple structure, easiness in platform integration, long-term operation and the like. Disclosure of Invention In order to solve the technical problems, the invention provides a seawater surface temperature and salinity synchronous measurement system and a seawater surface temperature and salinity synchronous measurement method, so as to achieve the purposes of synchronously inverting the seawater surface temperature and salinity by utilizing the integral statistical state of an optical field in a single optical channel, and improving the environment disturbance resistance capability and long-term operation stability of the system. In order to achieve the above purpose, the technical scheme of the invention is as follows: A seawater surface temperature and salinity synchronous measurement system, comprising: the light source module is used for generating an incident light signal; the optical sensing module is arranged on the surface layer of the seawater and is in direct contact with the seawater medium, and is used for forming an output light field with statistical characteristics under the interaction of light and the seawater medium; The light field sampling module is used for sampling the intensity distribution of the output light field to obtain light field statistical data; The data processing module is used for constructing a probability model of light field intensity distribution based on the light field statistical data, extracting statistical entropy characteristic quantity representing the overall statistical state of the output light field, and inverting to obtain the sea water surface temperature and the salinity by utilizing the response relation of the statistical entropy characteristic quantity along with the sea water te