为了解决船舶气象仪通信和图形显示的突出问题,提出基于Qt的软件设计思路,详细阐述了船舶气象仪的串口通信、以太网通信、数据存储和数据图形显示的实现方法.测试结果表明,该软件运行稳定,通信和图形界面的功能达到了预期的设计需求.

海上能见度的观测对航海安全日益重要。从能见度影响因素和测量原理出发,介绍了大气能见度观测方法,对海上能见度观测研究现状进行了汇总,提出了海上能见度观测中存在的问题和难点,认为能见度定义的准确性、光学系统污染会对能见度观测结果产生重要影响。由于搭载平台空间有限及自身的特殊性,海上能见度通常采用"以点代面"的方式进行观测,而搭载平台的自身发热和运动是测量不准的主要原因。最后对海上能见度观测的趋势和方向进行了展望。

The capacitance signal processing is one of key technologies of capacitive precipitation gauge.A capacitance meas-uring circuit based on dual 555 timers was designed.The measured capacitance was put in the oscillation circuit produced by the dual 555 timers, and the oscillation frequency could change when the capacitance changed.The oscillation frequency could subse-quently be transformed into voltage signal by phase distinguish, integral and amplified circuit.The components and parameters of circuit were chosen by calculation so that the relationship between input capacitance and output voltage could be linear.The linear relationship and the feasibility of the circuit are confirmed by experiments.

Focusing on ship of the requirements for medium and small information monitoring terminal,a kind of design scheme based on AVR MCU is put forward.It takes AVR MCU as a core,realizes the control for LCD module adopting LCD controller RA8835.By means of the close combination of hardware and software,it realizes real time display for excellent pictures and texts,and the adjustment of LCD contrast.The test result shows that the terminal displays clearly and works stably no matter in high temperature and high humidity environment or in low temperature and high humidity environment.

In maintenance of marine meteorological instruments,it is difficult on fault diagnosis and the maintenance staffs are requested with high skills,and it is not reality for specialists to work on site.Thus a portable simulator of marine meteorological instrument is developed.The hardware of the simulator is in modular design,main modules are all embedded systems based on AVR single chip computers with low power consumption;the connections among the modules are through CAN bus,and configurable according to needs.The software is designed with the expert system based on expert knowledge library and fault tree analysis,and the fault diagnosis model.The results of test show that rapid identification and precise locating for the faults can be done with the simulator;and the serviceability and maintainability of marine meteorological instruments can be improved effectively.

The priniciple of high precision analog conveaer AD421 and its application in the design of the Meteorological Instrument Simulation Equipment were introduced in the article.The design scheme uses uhralow-powcr 8 bit single-chip AT90CAN128 as the central controller and chooses the other ultralow-power external chips,which has designed the Meteorological Instrument Simulation Equipment which includes the 4—20 mA two-wire current output. The application shows that it has some traits such as uhralowpower, high precision and working stability.

First of all,it's very important to gathering data of turbulence wind field for building mathematic model.This paper presents the data-gathering software for the characteristic of turbulence wind field by VC++,using MSComm control to achieve serial communication,real-time display wind speed curve that is draw by using the function of Moveto Lineto,Dealing data with corresponding weather criterion,while the collected data is stored by Database format.It has been proved that this software is steady and credible,afford important basis on setting-up math model.

The test system of ship meteorological instrument was developed to satisfy the maintenance of ship meteorological instruments,which composed of information processing terminal,testing module of main instrument and testing module of sensors.Each of these modules included an embedded system based on microcontroller of AVR series and communicated with other module by CAN bus.The results show that the test system can judge the fault of ship meteorological instrument quickly and shorten the fault detection time as much as 60% compared with simple manual troubleshooting.