In this paper, we described a distributed strain measurement scheme in one-dimensional. The sensing information
of FBG is demodulated by a CCD spectrometer, the discrete strain is achieved by fitting and processing discrete
signal demodulated utilizing labVIEW virtual instrument technology. Then it could be achieved by Using
polynomial fitting method to one-dimensional discrete strain distributed detection. Experimentally, measurement
was implemented in Cantilever to prove the system performance. The experimental result shows that the system
can reflect the strain distribution in one-dimensional and an order strain modal characteristics of cantilever
accurately. The detection system can achieve real-time and dynamic measurements, the response time for 2kHz,
the response accuracy for 4μ(epsilon).
In this study, an innovative temperature-insensitive and no adhesive package for FBG pressure sensor was designed. We presents an package construction to compensate for temperature deviation of a FBG by mechanical properties of different metal materials; the package realize no adhesive utilizing combined technique of electroless plating NI-P and electroplating NI and laser spot welding technology. On the basis of the study on the Material structural properties and the compensation principles analysis of the FBG, the finite element method is used to analysis of the feasibility of the construction and optimize the construction parameters. The results show that this compensation construction can effectively reduce the temperature sensitivity of the FBG.
We present a theoretical analysis and a comparison to experimental results on self-mixing interference. From the theoretical analysis and experiment, the error of the velocity measurement, which is caused by a speckle pattern, has been investigated and optimization of the laser diode velocity system by selecting suitable experiment parameters and proper signal processing methods has been reported. The actual measurement error is <3.1% over a wide velocity range (5.2-479 mm/s).
Based on the Michelson interferometer, we use the circulator to realize the dual-path detection of the vibration signal,
which reduce the intensity noise caused by laser source. Reflectors are connected to the terminal of the signal arm and
reference arm respectively. The phase generated carrier (PGC) technology should use piezoelectric ceramic (PZT) to
generate carrier signal with high frequency in traditional demodulation techniques. Whereas the PZT is sensitive to the
external environment changing, so accuracy of vibration measurement will fall down, in order to solve this problem the
fiber waveguide modulator was used in the system instead of PZT. Then we use arctangent algorithm instead of PGC
algorithm to demodulate the signals, which could greatly simplify the algorithm. The output of the signals are input
into the computer through the data acquisition card and then demodulated by arctangent algorithm compiled by Labview.
Theoretical analysis and experimental prove the phase orthogonality of the two output signals, the amplitude and
frequency of the vibration signal can be detected at the same time. The Experiment results indicate that the system can
demodulate the vibration signal accurately.
MODIS a moderate-resolution imaging spectroradiometer instrument on board EOS-AM1 and PM1 has 36 spectral bands amongst which only 9.6 μm band sensitively traces atmospheric ozone. To produce total ozone inversion one requirement is via temperature and pressure profiles a popular requirement of mass-calculation which could now be argued not a literally convenient idea. Thus in this paper I try my hand at a new method through firstly overall bands' correlative statistics and analysis based on MODIS high-precision data source in spectral radiation to materialize "similar TRIPLET" spectral data combination method. Then it comes to us a need to attain a solid cooperative optimization and thirdly with forgoing output a process is introduced here of spectrum differential calculation leading to final total ozone inversion.
A method for the measurements of atmospheric transmittance by FTIR spectrometer is proposed. Calibrating special response of system based on two-point temperature with blackbody, transmittance spectra of CO2 IR absorption band are analyzed and calculated depending on the measurement data. The CO2 concentration in atmosphere is acquired after fitting the measured spectra with the line parameter in HITRAN employing NLLS algorithm. The results agree with the standard CO2 concentration considered in the environmental monitoring. It indicates that the method is feasible for measuring atmospheric transmittance and analyzing gases in quantity.