Based on the abundant optical image measurement data from the optical measurement information, this paper puts forward the method of evaluating the rocket flight stability performance by using the measurement data of the characteristics of the carrier rocket in imaging. On the basis of the method of measuring the characteristics of the carrier rocket, the attitude parameters of the rocket body in the coordinate system are calculated by using the measurements data of multiple high-speed television sets, and then the parameters are transferred to the rocket body attack angle and it is assessed whether the rocket has a good flight stability flying with a small attack angle. The measurement method and the mathematical algorithm steps through the data processing test, where you can intuitively observe the rocket flight stability state, and also can visually identify the guidance system or failure analysis.
A LED lidar system program was proposed for atmospheric aerosol detection. Compared with the conventional lidar using the laser, this system employs LED as the detection light source. Due to the wealth wavelength of LED, LED lidar achieves aerosol detection at a specific wavelength, and it makes the detection of aerosol particle size distribution easier. This paper presents a pulse modulation system for high-power LED light source. The system consists of pulse generator, narrow pulse driving circuit, and high-power LED array. A FPGA system is designed to generate the pulse whose frequency is adjusted by remote control. Using avalanche switching characteristics, the avalanche transistor circuit produces ultra-narrow pulses to drive the high-power LED array. Using U.S. standard atmospheric model, the detection capability of LED lidar system was simulated. Simulation result shows that the designed LED pulse light source used for lidar can meet the requirements of lower atmospheric aerosol detection.
A lysimeter weighing system based on fiber Bragg grating (FBG) sensor for measuring the soil water evaporation was presented in this paper. By the use of three mechanical levers and balance weight, the weight loaded on the FBG sensor was reduced K times (here, K was the ratio of levers). So the amount of water change in the soil container of tons can be weighted. A two-hole cantilever was selected as the elastomer structure of FBG weighing sensor, and an optimum design was carried on using the finite element method to meet the small-scaled design requirements. Using the matching fiber Bragg grating demodulation method based on LabVIEW, the demodulation system was easy to be implemented. Then the FBG center wavelength drift was converted into a time interval, and the weight can be obtained automatically through measuring the interval by computer. Preliminary experiment showed that this weighing system has the ability of measuring soil water evaporation accurately.
Dust aerosol or sand storm has become the popular attention topic of the world currently. In order to understand and
study the aerosol optical properties, particularly for dust aerosol produced in the spring weather condition, and to
investigate their effects on atmospheric pollution status, a Mie scattering lidar was developed to detect the time and
spatial distribution of the aerosol and the atmospheric visibility at Xi'an, China. The lidar system employs a Nd:YAG
pulsed laser at a eye-safe wavelength of 355nm as a transmitter, and a Schmidt-Cassegrain telescope as a receiver. A
spectroscope filter combined with a high-resolution grating was used to separate the main lidar returns and to block the
solar background simultaneously for daytime measurement. The observation experiments with lidar have been carried
out from the spring of 2007. The data of the extinction coefficients of aerosol and atmospheric visibility taken under the
different atmospheric conditions are demonstrated. The comparison results of visibility measurement using lidar and
other tool show that the lidar system is feasible, and the aerosol observation results show that the main aerosol pollution
of Xi'an is from the floating dust aerosol, which is usually suspended at a height of near 1km.