Study Of Submarine Detection By Modulated Lidar On Optical Carrier

When the light through the medium it will be high-scattered especially backward scattered in seawater. This kind of luminous scatterance would badly reduce the resolving rate on object detect, this is the most primary disadvantage to use optics technology about remote sensing in seawater and atmosphere.Now we introduce a joint system including the detection and signal disposal technology of microwave radar, combining the luminous transmission character of lidar. This system will improve the detect capability based on the lidar detect system.There are many difficulties in the joint system's design, as how to send the modulated pulse or how to receive the optical pulse. After being multiscattered, we will lose a great deal of information. So we need take a effective modulated method and a effective coding method to load the information on the optical carrier sufficiency. Then take a effective receive method to distill the information sufficiency. With the proper frequency-filter method, to distinguish the non and least scattered photons from the more scattered ones, shows the advantages in the joint system.In this item, we analyze the character of lidar with pulse modulated by carrier wave transmitting in multi-medium, combine the technology currently, establish the signal transmit system model which contained the coding. In the signal send part ,we accomplished two method to modulated the optical pulse ,add the coding in the detect signal, do some research in new modulator and modulated drive circuit .In the receive part , we give a blue print to receive the optical pulse ,and by emulation experiment, we also prove the feasibility of this project, and do the discussion of how to choose and the bandwidth of the receive filter.