To estimate the correct dimension of the target on the underwater, we can use CCD camera and cast laser light strip onto the target, and then observe the displacement of laser light to get the dimension. Since the laser light will show on different situation, it's due to the surface of the target is not smooth. When we get the image from CCD camera, we need to calibrate the displacement of the laser light and return to the actual dimension of the target on the underwater. We know the optical distortion and non-linearity of the CCD camera will influence to get the correct image, also the location of camera is. That's the reason we need to calibrate the camera first. It was a mathematical way to explain the calibration of CCD camera non-linearity before. On this subject, we lay vertical and horizontal grid lines of 50 mm span on an acrylic plate. These grid lines are same as the longitudes and latitudes of the map. We estimate the target with the pair of interpolated longitude and latitude same as to be used to estimate the location of the point in the world coordinate system. And choose some targets with different size and form to use to verify the approach. By the way, we also test if there is any influence for the clear of water. The results indicate the error is under 3 \% when we catch the image on the underwater by a calibrated CCD camera.

Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 63-67).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 223-242). Available also in a digital version from Dissertation Abstracts.

Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Gregory E. Triplett Jr. Includes bibliographical references.

A new diagnostic technique for studying the turbulent mixing characteristics of supersonic mixing flowfields is developed and implemented in two Mach 3 mixing flowfields. The diagnostic utilizes simultaneous particle image velocimetry and quantitative planar laser-induced fluorescence of krypton gas to study the interaction between turbulent scalar and velocity fields. The fluorescence properties of krypton gas are determined; measurements of the pressure and temperature dependence of the collisional quenching rates and cross-sections are made for various mixtures with krypton. The gases tested in this fashion include helium, nitrogen, air, oxygen, and ethylene. Additional measurements are performed to measure the relative two-photon absorption cross-section for krypton gas. The non-dimensional quenching rates are found to follow a power-law dependence for temperature, while the pressure dependence of the total quenching rate is found to be linear. Two injection flowfields are studied for their general topology and kinematic characteristcs. The first injector model is a basic injector meant to serve as a baseline case; there are no hypermixing elements present in this model. The second model is an asymmetric, unswept hypermixing injector featuring 15 degree expansive ramps flanking a central block. These studies utilize particle image velocimetry in planar and stereoscopic configurations in various planes. Results for the mean flowfield show distinct differences between the two flowfields; the planar injector flowfield is shown to be highly two-dimensional and exhibits minimal coherent unsteady behavior. The hypermixing injector flowfield exhibits a highly three-dimensional wake, with a pair of stream-wise vortices driving both mean deviations in the flowfield and considerable vortical coupling in the span-wise direction. Simultaneous krypton PLIF and PIV are employed in the two mixing flowfields. An assay of the dependence of the krypton mole fraction calculations on the fluorescence signal is performed. The overall sensitivity and the resulting dynamic range of the calibration is dictated largely by the reference mole fraction. Additionally, several different theoretical models of the temperature dependence of the fluorescence signal are studied to assess their validity and influence over the PLIF calibration procedure. Finally, the technique is employed in the two mixing flowfields, and a brief analysis of the mean and unsteady behavior of the two is conducted. / text

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No description available.

The interaction of laser light with a parcel of air with a known density structure can result in one of three reactions. The simplest of these reactions is reflection. Depending on the nature of the density profile, that part of the light that is not reflected can be refracted or scattered. The extent of the refraction and scattering is determined by the density of the particles found in the air. This thesis investigates two concepts that use the above mentioned interactions. The first, the colliding shock lens (CSL) was proposed by Buccellato, Lisi and Michaelis (1993). This device uses the graded index (GRIN) lens formed by the collision of symmetrically arranged shock waves to focus a laser beam. Unfortunately, the first reported colliding shock lenses had optical apertures of the order of millimeters. This is hardly useful in realistic laser systems whose beams typically have a diameter of 10mm. The major part of this thesis involves the scaling up of the optical aperture of the CSL while simultaneously maintaining a fairly short focal length. We show how the behaviour of the CSL varies with factors such as input energy, electrical diameter, geometry and various other factors. By optimising the physical parameters a 1.5cm diameter lens is obtained having a focal length of 1.5m. We develop a simple scaling theory and run a simulation based on the fluid in cell (FLIC) method, and find good correlation in both cases between the experimentally obtained results and the theoretically predicted ones. As a further development of the work on colliding shock lenses we introduce a cylindrical colliding shock lens. This device is shown to be able to line focus a laser beam of 1cm in diameter. At this stage the focus quality is still poor and suggestions are made for further improvements. Lidar is an acronym for light detection and ranging. Such systems are based on the scattering of laser light incident on a parcel of air. We discuss the results of a campaign conducted during the period of June to November 1994 to study aerosol concentrations over Durban. Particular attention is paid to low level aerosols due to sugar cane burning over the Natal coast. These aerosols are known to influence local climate and since vertical profile studies have never been carried out, this investigation gives some useful insight into the atmospheric dynamics. We find that in June (the begining of the burning campaign) the aerosol loading in the lower atmosphere is low. However, there are very stable aerosol layers at 3km and 5km. The density of the aerosols in these layers are decoupled. In September, the turbulent atmosphere over Durban is found to destroy structure in the aerosol layers. Nevertheless, the aerosol loading is high. Scattering ratios and extinction coefficients are calculated to show the long and short term evolution of the aerosols. A new coefficient (the low altitude aerosol coefficent - LAAC) is defined as an indicator for aerosol loading in the lower atmosphere. This coefficient is compared with total column ozone values over Durban. An anti-correlatory behaviour is noticed. We also report the detection of an extremely high aerosol layer (60km) over Durban. This layer is believed to be sodium. The profiles are compared to satellite data to verify the first ever detection of a constituent at these altitudes in Southern Africa. / Thesis (Ph.D.)-University of Natal, 1996.

Providing intense, contamination-free beams of rare isotopes to experiments is a challenging task. At isotope separator on-line facilities such as ISAC at TRIUMF, the choice of production target and ion source are key to the successful beam delivery. Due to their element-selectivity, high efficiency and versatility, resonant ionization laser ion sources (RILIS) gain increasingly in importance. The spectroscopic data available are typically incomplete in the region of excited- and autoionizing atomic states. In order to find the most efficient ionization scheme for a particular element, further spectroscopy is often required. The development of efficient laser resonant ionization schemes for yttrium and astatine is presented in this thesis. For yttrium, two ionization schemes with comparable relative intensities were found. Since for astatine, only two transitions were known, the focus was to provide data on atomic energy levels using resonance ionization spectroscopy. Altogether 41 previously unknown astatine energy levels were found.