Study Of Iridium Satellite Application For The Polar Drift-Towing Ocean Profiler

Sea-ice forecast is one of the important measures of climate research and protection of sea-route.For the sea ice forecast timely in polar,D-TOP(Drift-Towing Ocean Profiler)is jointly developed by Northeast Normal University,Ocean University of China and others.It is a special buoy system for the polar regions integrating the meteorological data on the ice and shallow hydrological data.The early development work of D-TOP has been completed with Argos satellite communication system.But it also has some problems,such as long delay time,data loss,limited transmission data size per day,inconvenient two-way transmission,and complexity of data processing.This paper will study the remote data transmission for D-TOP.We design a application scheme of satellite communication in mobile communication system based on Iridium satellite.And it has implemented some specific functions such as the low power,low loss rate of data transmission,the strong real-time properties,a multifunction client software and remotely controllable operation of the buoy system.The iridium model 9602 is the core of scheme with its SBD(Short Burst Data)services.Specifically,at the D-TOP,we complete the design of controllable power supply circuit for model iridium 9602 and power conversion interface compatibly with Arogs communication scheme.Making the adapter plate of Iridium9602 with antenna interface which is also compatible with the Arogs communication scheme.For the low power operation and high efficient data transmission of modules,establishing two-way transmission program with functions includeing detection of satellite signal,multiple transmission of buoy data,voluntary abandonment mechanism when overtime according to the basic communication protocol of Iridium9602.According to the operation requirements of D-TOP,the program such as the modification of the buoy operation parameters and software reset of the host,can be designed to realize the remotely controlled function of the buoy.At user-side,we use IDE Delphi7 to develop the PC client software for iridium communication based on POP3(Post Office Protocol 3)and SMTP(Simple Mail Transfer Protocol)becasue of heavy work stress form the integration of bouy data,which caused by the limit of the number of bytes in the single transmission of SBD communication services.The client software has achieved the function such as the basic email receiving and sending,the screening of buoy data carried in the appendix of iridium SBD service email.And it can implement humanized display,merging,storage of buoy data.More,each part of the iridium communication scheme were carried out functional testing in this paper.Then,we assemble D-TOP with iridium communication,and do some joint tests in laboratory and Baishan lake.Fanlly,the D-TOP is successfully placed in the Arctic.The experiment proves that the buoy system works well.Obviously,the software and hardware design of the iridium communication scheme realizes the low power operation,high efficient transmission of date and remote control of the buoy.And the design and application of PC client software greatly alleviates the pressure of user for the integration of buoy data.