In order to collect the information of temperature and strain field distribution information, the novel FBG detection system was designed. The system applied linear chirped FBG structure for large bandwidth. The structure of novel FBG cover was designed as a linear change in thickness, in order to have a different response at different locations. It can obtain the temperature and strain field distribution information by reflection spectrum simultaneously. The structure of novel FBG cover was designed, and its theoretical function is calculated. Its solution is derived for strain field distribution. By simulation analysis the change trend of temperature and strain field distribution were analyzed in the conditions of different strain strength and action position, the strain field distribution can be resolved. The FOB100 series equipment was used to test the temperature in experiment, and The JSM-A10 series equipment was used to test the strain field distribution in experiment. The average error of experimental results was better than 1.1% for temperature, and the average error of experimental results was better than 1.3% for strain. There were individual errors when the strain was small in test data. It is feasibility by theoretical analysis, simulation calculation and experiment, and it is very suitable for application practice.
In order to obtain clear two-dimensional image under the conditions without using heterodyne interferometry by inverse synthetic aperture lidar(ISAL), designed imaging algorithms based on filtered back projection tomography technique, and the target “A” was reconstructed with simulation algorithm by the system in the turntable model. Analyzed the working process of ISAL, and the function of the reconstructed image was given. Detail analysis of the physical meaning of the various parameters in the process of echo data, and its parameters affect the reconstructed image. The image in test area was reconstructed by the one-dimensional distance information with filtered back projection tomography technique. When the measured target rotated, the sum of the echo light intensity at the same distance was constituted by the different position of the measured target. When the total amount collected is large enough, multiple equations can be solved change. Filtered back-projection image of the ideal image is obtained through MATLAB simulation, and analyzed that the angle intervals affected the reconstruction of image. The ratio of the intensity of echo light and loss light affected the reconstruction of image was analyzed. Simulation results show that, when the sampling angle is smaller, the resolution of the reconstructed image of measured target is higher. And the ratio of the intensity of echo light and loss light is greater, the resolution of the reconstructed image of measured target is higher. In conclusion after some data processing, the reconstructed image basically meets be effective identification requirements.