Design And Realization Of Eco-hydrological Data Acquisition System Based On SDI-12Interface

With the development of computer network and information technology, It promotes thedevelopment of eco-hydrological data acquisition system to the fields of network, informationtechnology, intelligence and standardization."The Heihe comprehensive research of remotesensing" is a large-scale remote sensing research, which is conducted by the west actionprojects under Chinese Academy of Sciences "Heihe River Basin remote sensing-ground-based observations synchronization test and comprehensive simulation platform" andNational Key Basic Research and Development Program" Epicontinental ecologicalenvironment elements of active and passive remote sensing inversion together theory andmethod ". The research is conducted in the second largest inland river basin, the Heihei River.According to the requirements of joint observation test, Eco-hydrological data acquisitionsystem based on SDI-12bus is designed.The main work of this thesis is summarized asfollows:(1) Data collection terminal based on SDI-12bus is designed, which includes the maincontrol system, GPS module circuit, GPRS communication module circuit, LCD, SD cardmemory circuit and real-time clock circuit. This thesis introduces a bus technology and takesHydra Probe Ⅱ Soil Sensor for example to introduce the implementation in detail. Meanwhile,the protocol is introduced. The theoretical analysis and experimental results show that theprotocol is correct.(2) Embedded software platform is successfully built and μC/OS-Ⅱ real-time operatingsystem is transplanted to MC9SXS128single-chip. It can complete the task scheduling ofacquisition, storage, transmission, display and can improve the stability and efficiency of thesystem. FatFs file system is successfully transplanted to realize reading and writing functionand storage function of SD card.(3) Wireless communication module is been implemented, so the eco-hydrological datathat collected in the terminal can be transferred to the server via the GSM and the Internet.(4) Server-side program based on B/S architecture is designed. The server receives datafrom collection terminal. Then the data is stored and managed. The browser can view thesystem acquisition conditions, can query historical data and can also draw the data curve. Theserver uses the Java to develop while the databases adopt SQL Server2005. Eco-hydrological data acquisition system based on SDI-12bus is designed in this paper.This system has the function of real-time monitoring, curve drawing and historical dataquerying. Prototype testing shows that the system can operate stably and reliably so thesystem has good application prospects.