Abstract:The phosphorus content of apple tree canopy is estimated by using a hyperspectral remote sensing technology. Firstly, a Field Spec 3 type field spectrometer from ASD company is used to measure the hyperspectral reflectance of apple tree canopy in the shoot growth stopping period in spring. The measured spectral data are processed in a variety of transformation forms. Then, correlation of the data with the phosphorus content is analyzed. The spectral parameters more remarkably correlated with the phosphorus content are found. A phosphorus content estimation model is established after the regression analysis is made. The result shows that the near infrared band is the sensitive band of the phosphorus content of apple tree canopy. The wavelengths of 808 nm, 921 nm, 1195 nm and 1272 nm and the normalized infrared spectral index combined by these wavelengths are highly correlated with the phosphorus content of apple tree canopy. This is verified in the established estimation model. This research not only realizes the fast estimation of phosphorus content of apple tree canopy, but also provides the theoretical basis for the real-time diagnosis of nutrition of apple trees.

Abstract:Infrared stealth technology is very important in military applications and the stealth coating material is a crucial part in the infrared stealth technology. Firstly, according to the Stefan-Boltzmann law and Kirchhoff law, the principle of infrared stealth is analyzed and the category of infrared stealth coating is presented. Through analysis of different influence factors of coating composition, the ideal coating structure with low infrared emissivity is derived. Then, the research progress of different infrared stealth materials is presented. Their development trend is predicted. The future research will include the fabrication of new stealth materials and the combination of various stealth technologies.

Abstract:Quality evaluation of fused images is one of the problems to be solved badly in image fusion at present. In different scenes, both choosing proper fusion algorithms to improve the existing fusion algorithm and studying new fusion algorithms are very important. The objective quality evaluation methods with no reference are overviewed. The image fusion quality evaluation method based on structural similarity is described. Finally, the development trend of image fusion quality evaluation methods is discussed.

Abstract:ZnO films are deposited on Al2O3 (0001) substrates in the temperature range from room temperature to 800 ℃ by using a pulsed laser deposition (PLD) technique. The influence of substrate temperature on the surface morphology, crystallinity and photoluminescence properties of ZnO films is analyzed by using X-ray diffraction, atomic force microscopy and photoluminescence spectroscopy respectively. The result given by the atomic force microscopy shows that the structure and crystallinity of the ZnO films are improved gradually when the substrate temperature is increased from room temperature to 400 ℃ and are reduced when the substrate temperature is increased up to 400 ℃. The ZnO films grown at the temperature of 400 ℃ have the best surface morphology and crystalline quality. The measurement result obtained by photoluminescence spectroscopy at room temperature shows that the ZnO films grown at the temperature of 400 ℃ have the highest ultraviolet emission intensity at its shortest emission wavelength of 386 nm.

Abstract:Thermal images and reflectance spectra of cotton canopy were acquired by using a radiometric video camera from Fluke company and a portable non-imaging hyperspectral spectrometer from ASD company in five growth stages of cotton respectively. The thermal images were processed and the crop water stress index (CWSI) was calculated according to Jones' definition. Through spectrum analysis, both the reflectance spectrum at the wavelength of 654 nm and the first derivative spectrum at the wavelength of 738 nm were considered as the sensitive wavebands of the CWSI. The linear correlation model equations were established. The regression function accuracy values were 72.4% and 80.5% respectively. The research result showed that by using infrared thermal imaging technology to acquire high spatial resolution information of crop canopy, the effects of background interference factors could be eliminated and the CWSI of cotton canopy could be calculated more accurately. Compared with the reflectance spectra, the first derivative spectra was more suitable for the real-time and dynamic calculation of the CWSI of cotton.

Abstract:To measure the air-sea heat process in a small scale by using an infrared camera is of great scientific significance. However, the imaging nonuniformity of the uncooled infrared focal plane array used in the infrared camera has severe influence on the observation of sea surface temperature distribution. By using the calm water surface as a blackbody, the nonuniformity of the infrared camera is corrected and the stripe noise is removed. By comparing the Normalized Mean Square Error (NMSE), signal-to-noise ratio and standard deviation of the images processed via different filtering methods, the Gaussian filtering method is found to be more effective.

Abstract:According to the fact that the background of a small infrared target is sparse in the searching stage, a novel target locating method which uses a salient map based on the phase spectrum in an image is proposed. Compared with the traditional target search method based on sea-sky-line or coastline, this method has reduced its computational complexity greatly and overcome the shortage that the sea-sky-line or coastline can not be located accurately due to the unstable temperature. Compared with the method using an Itti model, the algorithm has overcome the weakness that the target can not be separated from the background. Two methods which use Discrete Fourier Transform (DFT) and Discrete Cosine Transform (DCT) to calculate the image phase spectrum are presented and their consistency is proved. A mathematic model which uses phase spectrum to calculate saliency map is established. Parameter selection of the model is explained. The theory and examples show that this algorithm is feasible and efficient.

Abstract:Infrared thermal imaging technology has a wide application prospect in the field of building engineering. The influence factors in wall hollow defect detection by infrared thermal imaging are summed up and analyzed by using a H2640 type infrared thermal imager and the NS9200 Report Generator software. The influence of weather, shooting angle and image analysis software on the detection result are discussed and hence the best shooting time and angle are determined. Finally, the misjudgment factors and level\&span range calibration of the image analysis software are analyzed and the corresponding processing measures are proposed.

Abstract:A spectrally tunable light source is presented. The light source can be used to create a wide variety of spectral power distribution. The design of a spectrally tunable light source system includes thousands of high power light emitted diodes (LEDs) across the whole visible spectral region. Besides being used to calibrate optical remote sensors, the spectrally tunable light source can be used for the detection calibration of photometers and radiometers. By using this system to simulate different lighting conditions, the material property and object reflectivity can be assessed. In addition, this system can also be used in displays.