The Prediction Analysis Of EMC Between Data Transmission Systems And Satellite-borne Prospecting Equipment

In seismic electromagnetic exploration satellite, data transmission systems composed by digital transmission power and digital transmitter. Fitting equipped in space-borne detecting equipment contain dual-frequency GPS detecting instrument, induction magnetometer, electro field probe, fluxgate magnetometer, plasma analyzer, Langmuir probe, high-energy particle detector and so on. The thesis completes electromagnetic compatibility (EMC) for prediction between digital transmission systems and space-borne detecting equipment.Firstly, starting from the three elements of electromagnetic interference, paper identified that interference source is data transmission system, interference nature is the radiation interference and sensitive equipment is space-borne detecting equipment. Based on the function of space-borne detecting equipment, it can be divided into the digital and digital simulation detection equipment, electromagnetic detection equipment and dual-frequency GPS detecting instrument. Paper develops a specific EMC standard and identified the EMC prediction program process between data transmission system and space-borne detecting equipment combined by equipment index, the requirements of GJB151A-97 and GJB461 for the different categories equipment. Then, the earlier research work is using the geometric optics theory (GO) and the uniform geometrical theory of diffraction (UTD) and based on the modified data transmission antenna radiation orientation image. Combined with the design specifications and characteristics of digital transmitter and dual-frequency GPS detecting instrument, follow the power of interference margin prediction equation, paper establishes data transmitter model, dual-frequency GPS detecting instrument model, data transmission antenna model, dual-frequency GPS detecting instrument antenna model and transmission loss model. Utilizing the frequency scalping method, power scalping method, bandwidth scalping method and the antenna effect scalping method, paper completes the EMC for the data transmitter and dual-frequency GPS detecting instrument. Paper completed EMC for data transmitters and space-borne detecting equipment though the method of amplitude comparison. Finally, using Gaussian function, paper simulates the power supply transient surge current for the data transmission. By analyzing the relationship between the area of data transmission supply power circuit and the current work wavelength, paper analysis the radiation interference for surge current through selecting the appropriate radiation model. Paper concludes that the strongest radiation interference occur when the frequency is 3500Hz, and analysis the degree of influence for space-borne detecting equipment.According to the analysis, data transmitters and dual-frequency GPS instrument are not compatible. Interference can be ignored when the distance between induction magnetometer and data transmission is beyond 1.2m. Digital transmission system with the plasma analyzer, Langmuir probe, high-energy particle detector, the electric field detector and fluxgate magnetometer are compatible. Though it's a pre-research questions, the prediction model and the predict principle in paper are considerable reference value for the actual application.