Design Of Doppler Log Echo Signal Simulator

Doppler log is a measuring device which is used to measure the range and speed of ship, it has broad application and high precision.By launching acoustic to the bottom of sea at a certain angle, by testing frequency deviation, the Doppler log measures the speed of ship relevant to seabed or water layer. But the tests of the device are done on sea or pool usually, the shortcomings are long cycle and high cost. In response to these situations, this thesis designs an echo signal simulator which can output four analog signals of phased-array Doppler log’s echo signal.In this thesis, the relevant principles of the system are described, including measure principle of velocity, principle of phased-array, broad-brand code signal and how the model of phase-code is selected, then according to the Doppler log echo signal model, characteristics and relevant parameters,the designed program of the system is decided. Based on the designed program, hardware circuits and software program are designed. Hardware circuits contain the peripheral circuits of the S3C2440 controller with ARM920T kernel, circuit of D/A conversion and circuit of power. Finally, the corresponding software is programmed.