Marine Environmental Monitoring System Based On LoRa Wireless Sensor Network

Environmental monitoring technology is of great significance in the exploration of marine resources,protection of marine environment and early warning of marine disasters.But the marine environment is changeable,the marine monitoring is difficult and costly,especially the precise monitoring is difficult to realize.Moreover,marine disaster events are sudden,and it is a great challenge to discover and deal with marine pollution in time.It is a hot issue in the field of marine monitoring how to realize the automatic measurement of various environmental parameters quickly and accurately,guarantee the quality of long-distance transmission of monitoring data,and construct the marine monitoring network in the vast sea area.As the core technology of Internet of things,wireless sensor network can solve this problem effectively.Therefore,this paper designs the marine environment monitoring system based on LoRa Wireless Sensor Network + 5G.The terminal node adopts the LoRa communication mode to construct the maritime monitoring network,and the gateway adopts the heterogeneous communication mode of LoRa + 5G to realize the Remote data transmission.The terminal node collects water quality parameters such as total phosphorus,Chemical oxygen demand,ammonia nitrogen,pH and dissolved oxygen in real time,and then modulates the data into LoRa radio frequency signal and sends it to the gateway.The gateway receives and demodulates the LoRa radio frequency signal,and sends the data as 5G packets to the cloud platform.The back-end server calls the API interface of the cloud platform to provide the user interface and realize the data visualization.System software design to achieve low power terminal node operation,when the data upload cycle is set to 15 minutes,the capacity of 5800 mAh 12 V lithium battery can support terminal node operation for 257 days.The sea communication range of LoRa is tested by using the terminal node and gateway.The test results show that the signal strength of the gateway decreases with the communication distance increasing.In the range of 200 ～ 1600 m,the decrease of signal strength does not affect the success rate of communication between the terminal node and the gateway,and the success rate of communication decreases slightly from 1600 m to 2000 m,which proves that LoRa has reliable long-distance communication performance in the range of 2000 m.Finally,the system’s maritime network communication function is tested,the experimental site is Zhanjiang Bay Area.After the terminal node enters the network successfully,every 15 minutes uploads the monitoring data to the gateway,the backstage server receives and updates the monitoring data in real time,and draws the curve chart according to the historical data.During the 30-day work,the terminal node sent 8640 data,22 packet loss,the loss rate is 0.25%,which proves the stability of the system network performance.The system realizes remote data acquisition,processing and release with low power consumption on the sea,and the system has good stability of data continuous transmission and safe and reliable communication.