The Visualization Monitoring System And Lightning Protection Design Of The Automatic Weather Station

As the main way of surface weather observations, automatic weather stations (AWS) improve the efficiency of meteorological observations by overcoming the defects such as low temporal and spatial distribution density and low accuracy of artificial observations. However, due to long-running outdoor, AWS is vulnerable to the interferences of various factors. Therefore, in order to maintain normal operation of AWS and improve the accuracy of meteorological observations, it is very necessary and significant to make research on guarantee technology of AWS.This paper analyzes the problems encountered in the operation of an automatic weather station, researches the measures of AWS guarantee technology, the AWS visualization monitoring program is proposed, and the AWS visualization monitoring system is designed with embedded technology, which achieves the visualization monitoring and management of the automatic weather station. Meanwhile, the lightning protection method of AWS is studied, including such designs as grounding system, direct lightning protection, induction lightning protection, to prevent the damage posed by lightning over-current on the automatic weather station equipment. The specific research contents include:Using the original connections between the meteorological elements sensor and collectors on AWS, adding a main control board used for monitoring and a C328camera module, reusing the original communication means of the AWS, the whole program of the visualization monitoring system is developed.Using ARM7architecture LPC2387chip, functional circuits such as the smallest system, serial communication ports, CAN bus and storage circuit are designed, which consist of the hardware platform of the monitoring system, according to the monitoring requirements, three hardware approaches including host computer command, RTC timing and infrared sensing are proposed to drove the C328camera module.As to software, the cut μC/OS-II operating system is transplanted to the LPC2387processor. Then the priorities of such four tasks as data transmission, C328driver, command receiving and processing and meteorological elements data receiving and processing are divided, through two communication mechanisms of mailboxes and semaphores, quick tasks switch and data transmission can be achieved.The technology and method of AWS lightning protection are analyzed and researched, joint hared grounding grid designed with specific specifications grounding electrode under the bservation site is introduced to reduce the potential difference among the ground screens, so that the lightning current discharges into the earth. Erecting the lightning rod on the wind shaft by the standard construction, the AWS equipments can be protected against the damages posed by direct lightning flash. Surge protective device is installed at the RS485interface and power port to avoid the over-voltage impact of the induction lightning, ensuring the security of data transmission and the power supply; the2-level lightning protection is adopted at the power connector on the PCB board to prevent the damage on the core chips of control system posed by the over-voltage.An AWS outfitted the visualization monitoring system and lightning protection measures me ntioned above has been running in the field more than one year, and satisfactory results are obtain ed, the experiment results show that the monitoring system can ensure the reliable access of the meteorological elements information, real-time monitoring on the running AWS can be achieved, and the monitoring system is stable, reliable and easy to transplant. Though the practical applicati on, the lightning protection measures can effectively protect the automatic weather station from t he damage posed by lightning, and the lightning protection measures are normative and reasonabl e, worthy of promoting.