Engineering topics
Publications and source records attributed to Wilkerson, T. D..
The establishment of a center for remote sensing was proposed to provide the following: (1) service, research, and education in the developing discipline of remote sensing; (2) effect multidisciplinary linkages between scientists and users of remote sensing and those who develop remote sensing techniques; and (3) strengthen and extend existing remote sensing capabilities into a cohesive program.
Experimental airborne lidar systems proved to be useful for shallow water bathymetric measurements, and detection and identification of oil slicks and algae. Dye fluorescence applications using organic dyes was studied. The possibility of remotely inducing dye flourescence by means of pulsed lasers opens up several hydrospheric applications for measuring water currents, water temperature, and salinity. Aerosol measurements by lidar are also discussed.
Application of remote sensing techniques to the study of the Chesapeake Bay and the availability of the resulting information are discussed in terms of public awareness of the Chesapeake Bay, its total environment, and the need to protect that environment and to preserve the Bay. Recommendations given include: (1) continue the study of remote sensing technology and its use in the Chesapeake Bay region; (2) emphasize the importance of LANDSAT imagery to the evolution of remote sensing technological developments and the awareness of the environment and its changes; (3) increase dissemination of information of the environmental applications of remote sensing technology to the public; (4) design surveys of the Chesapeake Bay environment and its manmade changes; and (5) establish a coordinating regional institution to develop a management plan for the Chesapeake Bay.
The proceedings are presented of a conference, jointly sponsored by the National Aeronautics and Space Administration, the U.S. Environmental Protection Agency, and the University of Maryland. The purpose of the Conference was to assemble representatives of federal and state government agencies engaged in research on the condition and evolution of the Chesapeake Bay to compose a status report, to present current activities and future plans, and to recommend a long-range future course of policies and programs.
Experimental research on a near infrared tunable dye laser was reported, and theoretical simulations were presented for various lidar configurations. The visible and nearinfrared wavelengths considered were suitable for observations of aerosols, water vapor, molecular oxygen pressure and temperature in the troposphere and above. The first phase of development work was described on a ruby pumped, tunable dye laser for the wavelength region 715 to 740 nanometers. Lidar simulations were summarized for measurements of H2O and for two color lidar observations of aerosols in the atmosphere.
A tunable dye laser suitable for differential absorption (DIAL) measurements of water vapor in the troposphere was constructed. A multi-pass absorption cell for calibration was also constructed for use in atmospheric DIAL measurements of water vapor.
The feasibility was studied of measuring atmospheric water vapor by means of a tunable lidar operated from the space shuttle. The specific method evaluated was differential absorption, a two-color method in which the atmospheric path of interest is traversed by two laser pulses. Results are reported.
Work has been conducted to reduce substantially uncertainties concerning the line strengths for carbon and sulfur. Two or more independent methods were used to measure thermodynamic variables and to calibrate detectors for absolute sensitivity and spectral response. The absolute transition probabilities of 124 visible and infrared lines of C I, S I, and S II were measured in a consistent way.
Results of research on uranium and tungsten spectra are summarized. Measurements of visible line spectra and opacities were carried out on shock tube plasmas which, prior to shock compression, were mixtures of rare gases and UF6 or WF6. Opacities were compared to theoretical predictions. Feasibility of light source methods other than the shock tube was explored for future applications in the spectroscopy of heavy metals and ions.
High temperature plasmas optical properties measurement by plasma spectroscopy, using gas driven shock tube as light source
Absolute opacities of uranium plasma measured by using gas-driven shock tube
Halogens atomic transition probabilities spectroscopic measurements in visible and near IR spectra, using gas driven shock tube
Absolute emissivities of uranium plasmas in gas driven shock tube
Triggered spark source for multiply charged carbon ions applied to collision cross section measurements
Explorer 34 observations of hydrogen and He ions in solar wind, noting number density variations and tentative association with geomagnetic storms
Shock tube application to transition probability measurements with emphasis on thermodynamic state of radiating gas, noting temperature dependence of level population
Jump conditions across MHD shock waves, reducing relations to identities applicable to nonequilibrium situations
Solar plasma observations during magnetic storms, discussing shocks and tangential discontinuities, geomagnetic variations and He