Main menu >> Electrical and Computer Engineering >> Remote Sensing

Electrical and Computer Engineering

Remote Sensing
^ Holographic Velocimetry
R. J. Adrian* (Theoret. & Appl. Mech.); G. Papen, D. Barnhart; T. J. Hanratty (Chem. Engr.)
U.S. Office of Naval Research, N00014-90-J-1415; U.S. Department of Energy, DE-FG05-87ER75508; Argonne National Laboratory, ANL 828-62403

One of the goals of experimental fluid flow is to verify large computational models. This requires the remote measurement of the 3-D velocity vector within a flow. This project uses twin frequency-doubled YAG lasers to record two holograms of the fluid flow at two instants in time. The complete velocity field is then reconstructed by performing 3-D correlations of tracer particles within single volume elements (typically 1 mm3).

^ High Latitude Mesospheric Dynamic and Chemistry Studies
G. R. Swenson,* A. Liu
National Science Foundation, ATM 99-0859

Studies of atmospheric gravity waves in the mesosphere and aurora will be performed with imaging and spectroscopy instrumentation at the NSF backscatter radar facility in Sondrestrom, Greenland. The measurement studies will be complemented by radar measurements as well as all-sky imagery measurement provided by established instrumentation at the site. University of Illinois instrumentation includes a 4-channel photometer directed along the magnetic meridian, a CCD transmission imaging spectrometer, and a CCD all-sky airglow camera. Scientific objectives include the study of momentum and energy flux carried by propagating waves, chemistry associated with thin sporadic E and metal layers, and particle energy flux and beam characteristic energy of precipitating auroral particle beams. Image processing of 2-D spectrograms and 2-D images of atmospheric observations is a major activity with this program.

^ Imaging Studies of Mesospheric Gravity Waves
G. R. Swenson*
National Science Foundation, ATM 97-14620

Small-scale waves propagate from the lower atmospheric convection and mountain driven sources to the upper atmosphere. Existing chemiluminescence produce airglows, which are perturbed by the waves. Airglow imagers observe the perturbations and the horizontal wavelength and amplitude of the waves are measured. The waves carry momentum and energy, which can interact with the large-scale dynamics to cause major dynamic effects. Observations are made at Albuquerque, New Mexico, where the University of Illinois lidar (George Papen and Chet Gardner) measure wind and temperatures. Signal processing is accomplished to extract the intrinsic wave parameters and power and spectral characteristics of the horizontal wave structure.

^ Technology Development for the MIDEX WAVES Satellite
G. R. Swenson,* C. S. Gardner
National Aeronautics and Space Administration, NAG5-8569

This program involves the development of technologies associated with a multiple sensor remote sensing satellite designed to measure small-scale waves in the middle and upper atmosphere. These studies include specifically the demonstration of infrared sensor array technology. Array sensors are planned for 1.26 and 1.45 microns that can be operated at elevated temperatures (160 K) but retain low noise attributes. This technology allows passive radiators rather than active refrigeration, enabling the sensors to operate with low power at a reliable, long lifetime on a small satellite. Other technologies include the development of remote sensing signatures from optical emissions as indicators of atmospheric dynamics for both the stratosphere and mesosphere. Instrumentation includes both nadir and limb imagers and spectrometers as well as a Michelson interferometer to measure Doppler winds.

^ Advanced Solid-State Lidar for the Scott-Admundsen South Pole Station
G. C. Papen,* C. S. Gardner*
National Science Foundation, OPP 92-19898 DPP

Current models of ozone depletion over the Antarctic predict that some of the major chemical mechanisms occur on the surface of polar stratospheric clouds (PSCs). In addition, the energy-coupling mechanisms from the lower to the upper atmosphere over the Antarctic are not well understood. Researchers are deploying an advanced lidar system at the South Pole that is capable of measuring characteristics of the morphology of the PSCs. They will also measure upper atmospheric wave activity using Na as a tracer.

^ Testing of Parallel Optical Fiber Links
G. C. Papen
National Science Foundation, ECD 89-43166

Advanced optical interconnections based on parallel space division multiplexing using a fiber ribbon or wavelength division multiplexing using multiple wavelengths within a single fiber require new techniques to measure and model performance. These techniques are being developed because the aggregate data rates through these parallel spaces exceed 15 Gbits/s. Researchers are developing testing methodologies and equipment to test and model the performance of these high-speed data links.


Summary of Engineering Research