Design Of CTD Sensor And Research Of Data Processing Technology

The ocean is not only an important part of the global life support system, but also avaluable asset to the sustainable development of human society. With the shortage of landresources, population growth, environmental degradation and other issues is increasinglygrim, all coastal states have sights to marine, speeding up the development and utilization ofocean. CTD sensor is the main tools to the sea water temperature, salinity and depth of basichydrological information for the study of the the marine environment and resources, whichplays a very important role in weather monitoring, development of marine fisheries, defenseand military science and technology fields. Therefore, studying on CTD sensor measurementsystems and related technology have very important significance.First, the paper is based on the background and significance of the research task,analysis of domestic and foreign CTD sensor development and research status, and analysisof the principle of the measurement of various parameters.on this basis, advancing of theoverall scheme of CTD and designing of system index. And, Adopting STM32microprocessor and μC/OS-IIoperating system to build CTD sensor measurement syst-em’s development platform.Secondly, the purpose is to design a portable measurement system of CTD sensortemperature-depth sensor, modular design, the work is divided into three parts, which areincluding hardware design, software design and data processing. Adopting STM32microprocessor as the core control board chip in the hardware design, carrying on thetemperature acquisition circuit design, salinity acquisition circuit design, the depthacquisition circuit design and so on. The temperature acquisition is used in platinumresistance temperature sensor, which can quickly and accurately obtain the temperature ofseawater; salinity acquisition circuit design using a conductivity measurement of salinity,which can achieve high accuracy and easy to live measurements; depth acquisition is used inpressure sensor, which can easily calculate the depth of the ser water. In the software design,using the μC/OS-IIoperating system for the measurement system. In order to themanagement of system resources and the conveniently expansion of features, and applicationdevelopment, digital filtering algorithm is to eliminate noise and interference. so that thesystem can achieve high-precision data acquisition. The study for data processing portion, themain task is to use the RBF neural networks to compensate for the platinum resistancetemperature sensor to solve the non-linear problem; the data processing of salinity is using the new salts standard formula, by the three variables of temperature, conductivity and depthto obtain the value of the salinity; the data processing of depth is based on the linearrelationship between pressure and depth, the depth and the pressure sensor output voltage canbe derived directly relationship formula, so that results can be obtained directly, This methodcan be used in a similar measurement and control system.At last, the system is tested via lots of experiments to temperature, conductivity anddepth. the test results show that this CTD sensor measurement system meets the designrequirements.