The Research Of Wave Buoy Data Acquisition And Processing System Based On GPRS

China is a great coastal country with mainland coast more than18,000km andnearly300million km2waters can be managed. There are6,000islands of500m2ormore and more than1,000harbors can be took advantage of. Wave buoy is the mainequipment of long-term, real-time, fixed-point observation; it observes the wave height,wave period and wave direction continuously. Offshore wave observations play animportant role in ocean development, transportation, economic construction, nationaldefense construction and maritime vessels activities etc. The data collected by wavebuoy is of good continuity and precision; it is transmitted to the shore station by VHF(Very High Frequency) radio communication technology. After having received the data,the shore station will process, store, display, and print the data. But the distance of VHFradio communication is limited by various factors, such as the gain and height of theantenna, the output power of the transmitter, the sensitivity of the receiver,electromagnetic environment and obstacles. Even though the transmission distance ofwave rider, one of the advanced wave buoys in the world, is only50km. So this kind ofwave buoy system must set up a shore station system which needs sending people toguard, and that leads to a high cost. The harsh working conditions lead to a decline in itsstability and reliability.Traditional VHF radio communication technology is replaced by GPRScommunication technology in this thesis. GPRS provides data transmission servicebased on TCP/IP protocol. GPRS is well suited for applications of intermittentconnections initiated by small flow request which need frequent data transmission, suchas power systems, mobile office systems, public security systems, sewage treatment systems etc. In this thesis, SIM300GPRS module which is a product of SIMCOM isused for data receiving and transmitting. The solutions of SIM300embedded systemcan send wave data to the GPRS-Internet network; any host computer connected to thepublic network which obtained a public network IP (or the dynamic public IP obtainedby ADSL dial-up access) can receive wave data from the data acquisition system. Thehost computer can also send remote control commands to set the working mode of thewave buoy. The solution can save the cost of wave buoy system, and the stability andreliability is enhanced. That provides technical support of constructing a stable andreliable monitoring network of ocean waves.STC12C5A60S2MCU module is embedded into the data acquisition system, it willaccomplish the task of data acquisition, data packaging and data transmitting; waveheight and tilt sensor is used to collect wave height sequences and wave directionswhich are analog voltage signals; A/D converter ADC0809is a product of NationalCompany, it converts analog voltage signals to digital that can be processed by MCU.SIM300is the data communication module, SIM300is connected to MCU by serialconnection, MCU can send AT commands through serial port to control SIM300to sendand receive data. Data center is designed by Microsoft Visual C++, the communicationmodule is designed by using message-based asynchronous socket programming;Database module is designed by VC++ADO components, ADO component facilitate toorganize and manage the data effectively. Data processing module is designed by VC++and MATLAB mixed programming, export M files to DLL (dynamic link library) filesin MATLAB development environment, embed the exported DLL files into the VC++MFC project. That can be very simple to complete the data processing functions. Thedata center can run steadily and continuously after the test, accomplished the task ofreceiving and processing the data from the data acquisition terminal which proves thatthe solution in this thesis is feasible and reliable, it achieved the expected effect.