Abstract:Fourier transform spectrometers are widely used in the field of infrared spectroscopy. They are also the remote sensing instruments suitable for profiling atmospheric temperature, humidity and wind field and atmospheric composition. A Fourier transform spectrometer based on a Mach-Zehnder interferometer is proposed. A set of reflectors in the Mach-Zehnder interferometer move at a uniform linear velocity to vary the Optical Path Difference (OPD) between double arms linearly. Then, a balanced photo-receiver detects the interference signals from double paths differentially. Through the Fourier transform of the electric signals corresponding to linear optical path difference, the spectral distribution curve of input light can be obtained. Compared with the Michelson interferometer, the interference signals obtained by the Mach-Zehnder interferometer under the same optical flux input condition is stronger and the noise due to non coherence intensity is less. This result is of significance to the space remote sensing.

Abstract:When the attitude of a satellite or a flight vehicle is to be controlled, attitude measurement should be carried out by a sensor. Infrared earth sensors can obtain the attitude information by measuring local vertical lines. According to the characteristics of a linear-array infrared earth sensor, an algorithm is designed. In the algorithm, the measurement accuracy is improved through the subdivision of pixels and the application environment is expanded through the selection of multi operating modes. Software design and test are implemented on the product. The test results show that the algorithm has the characteristics of improving measurement accuracy and enhancing the adaptability to operating environment. It has an important promotion function for adapting earth sensors to the development of microsatellites, providing high accuracy attitude and implementing celestial navigation etc.

Abstract:In power systems, to use computer vision and image processing technologies to detect the faults in arresters plays an important role in their safe operation. An arrester fault detection method based on infrared images is proposed. The algorithm firstly preprocesses the input images and uses Scale-Invariant Feature Transform (SIFT) descriptors and K-means++ algorithm to train a vision dictionary to precisely position the arrester. Then, it uses Linear Spectral Clustering (LSC) to segment the area selected. Finally, it implements the detection of arrester fault by analyzing the characteristics in the thermal image of the arrester. The experimental results show that the proposed algorithm can detect the faults in arresters effectively.

Abstract:To improve the utilization of infrared satellite data, more data should be assimilated into the initial field of numerical forecasting mode so as to minimize the influence of cloud pollution. According to the data from Atmospheric Infrared Sounder (AIRS), a cloud detection method is used to identify Genting Height. After the validity of the method is verified, all of the channels above cloud top are retained in the cloud region of a large-scale satellite field of view and the brightness temperature data of these channels are assimilated into the initial field of the numerical prediction mode. By comparing and analyzing the simulated paths of the typhoon by different schemes, the influence of the cloud detection method on Typhoon numerical simulation is evaluated. The results show that the detection method is better in detection. The distribution of the clear sky and cloud area detected corresponds to the actual observation and the high cloud top area detected corresponds well to the typhoon cloud system. After the channel brightness temperature above cloud top is utilized, the utilization of infrared satellite data is improved greatly. The data utilized is 2.4 times as those of the original data. In typhoon path simulation, the increase in the amount of data makes the path simulation more accurate and is obviously close to the observed values after assimilation of above channel data.

Abstract:The influences of temperature change on the states of n-alkanes (n-undecane(C11), n-dodecane(C12), n-tridecane(C13) and n-tetradecane(14)) were studied by using terahertz time-domain spectroscopy. The terahertz time-domain spectra were obtained by scanning the samples at different temperatures. The spectra of frequency-domain, refractive index and absorption coefficient obtained after data processing could reflect the state change of n-alkanes. When the temperature dropped below its freezing point, the states of n-alkanes were converted from liquid to solid crystals causing the effective frequency range in frequency-domain spectra to narrow and the area of frequency-domain to decrease. The decrease of temperature could result in the crystallization of alkane molecules, the increase of refractive index and the linear dependence of absorption coefficient on frequency. The experimental results showed that terahertz time-domain spectroscopy could be used to detect the non-polar hydrocarbons represented by normal alkanes.

Abstract:To analyze the characteristics of the gravity waves excited by the deep convention stratosphere in the land area of China, the propagation characteristics of the gravitational waves excited by deep convention stratosphere accompanied with heavy rainstorm are analyzed. This analysis is carried out for a rainstorm event occurred over Jilin province on July 20, 2010. In the analysis, the observation data from the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite are used with the ERA-nterim field data and the S-transform wavelet analysis method. The possible influence of gravity wave propagation on rainstorm development is further discussed.

Abstract:The improvement of sleep effect of sleep disorders by far infrared ray (FIR) sauna and the changes of FIR imaging characteristics of their spleen-stomach areas in traditional Chinese medicine (TCM) were discussed. Several employees of our company were selected to be subjects. The sleep disorders whose cardiopulmonary coupling (CPC) sleep quality evaluation scores were less than 60 were brought into a standard. Among them, seven subjects accepted FIR sauna sleep intervention seven times in ten days. By comparing the CPC and FIR imaging characteristics obtained before and after FIR sauna intervention, it was found that three sleep specifications such as sleep quality (score), stable sleep duration (h) and unstable sleep duration (h) of the subjects were improved. The cooling-off phenomena of the spleen-stomach areas of five subjects were improved substantially. This indicated that their △T increased significantly (p=0.039). The results showed that FIR sauna intervention could improve the sleep effect of sleep disorders, which was reflected in the variation of temperature difference in the spleen-stomach areas in TCM. Meanwhile, this research also conformed to the "disorder of the stomach leading to insomnia with restlessness" in the theory of TCM.