Study And Implement Of Broadland Doppler Velocity Log Utilizing Integrated Receipt And Transmission Short Impulses

Doppler log is a precise instrument, which was designed by the means of Doppler Effect. In most case, the instrument is used to measure ship velocity which relative the earth or the flow of the water, and calulate its voyage. In recent years, requiement of precision of Inertial Navigation System is increased, and its precision is depended on the precision of velocitic parameter of the carrier which was measured. In view of the successfully application of instrument on the ship, This paper proposed the design of the Doppler log whitch was applicated on the carrier.According to the characteristics of the application of Doppler log on the carrier, This paper research it around the solution of the hardware of instrument and the algorithm of the software. The most works of this paper comprise three parts, the first is the design and the debugging of the hardware of the digital signal processing system and functional modules relativly; the second is the design and the achievement of the software according to hardware designed by us, the last is research of the algorithm of frequency of estimated which was used.The digital signal processing system is depended on controller TMS320F28335 designed by the TI Company. The relative functional modules is on the launch and receive circuit. To the launch circuit part, its driver circuit is TPS28225. To the receive circuit part, it comprises two controlled amplifiers and one band-pass filter because of the weakness back signals with noise.The relative functional modules contain two parts, one is that the 50 hz of katanami signal was launched by PWM module, and this signal was amplified by driver cicruit, then it was changed to the 50 hz sinusoidal waves signal by the Impedance match circuits of energy converter. The other is that back signal was received by the ADC module on the controller, in this process, the back signal was amplified by the controlled amplifiers which was controlled by the IO pins of controller.The algorithm of the changed frequency of the back signal is the one of the factors which impact the precision measurement. The current algorithm contains zero crossing point method PLL and Complex-correlation method. As the result of the simulation, the last one is the best method.