NASA Scientific and Technical Aerospace Reports

Time Stamping System, The Detection of Gravitational Red Shift by Transportation of Atomic Clocks, and Time Distribution
Using the Network.
CASI
Clocks; Frequency Measurement; Frequency Standards; Time Measurement; Timing Devices
20040120969 NASA Langley Research Center, Hampton, VA, USA
An Overview of Particle Sampling Bias
Meyers, James F.; Edwards, Robert V.; [1984]; 11 pp.; In English; Second International Symposium on Applications of Laser
Anemometry to Fluid Mechanics, 2-4 Jul. 1984, Lisbon, Portugal; Original contains color illustrations; Copyright; Avail:
CASI; A03, Hardcopy
The complex relation between particle arrival statistics and the interarrival statistics is explored. It is known that the mean
interarrival time given an initial velocity is generally not the inverse of the mean rate corresponding to that velocity. Necessary
conditions for the measurement of the conditional rate are given.
Author
Bias; Sampling; Velocity; Particles; Laser Anemometers
20040120970 NASA Langley Research Center, Hampton, VA, USA
Close-Range Photogrammetry with Video Cameras
Burner, A. W.; Snow, W. L.; Goad, W. K.; [1983]; 16 pp.; In English; No Copyright; Avail: CASI; A03, Hardcopy
Examples of photogrammetric measurements made with video cameras uncorrected for electronic and optical lens
distortions are presented. The measurement and correction of electronic distortions of video cameras using both bilinear and
polynomial interpolation are discussed. Examples showing the relative stability of electronic distortions over long periods of
time are presented. Having corrected for electronic distortion, the data are further corrected for lens distortion using the plumb
line method. Examples of close-range photogrammetric data taken with video cameras corrected for both electronic and
optical lens distortion are presented.
Author
Cameras; Photogrammetry; Video Equipment; Linear Transformations
20040120972 NASA Langley Research Center, Hampton, VA, USA
Fringe Formation in Dual-Hologram Interferometry
Burner, A. W.; [1989]; 6 pp.; In English; 5th International Symposium on Flow Visualization, 21-25 Aug. 1989, Prague,
Czechoslovakia; Original contains black and white illustrations; No Copyright; Avail: CASI; A02, Hardcopy
A first order geometrical optics treatment of holograms combined with the generation of interference fringes by two point
sources is used to describe reference fringe formation in non-diffuse dual-hologram interferometry.
Author
Geometrical Optics; Diffraction Patterns; Holographic Interferometry; Mathematical Models; Flow Visualization
20040120979 NASA Langley Research Center, Hampton, VA, USA
Multi-Element Electron-Transfer Optical Detector System
Jordan, Jeffrey D., Inventor; July 20, 2004; 6 pp.; In English; Original contains black and white illustrations
Patent Info.: Filed 13 Mar. 2002; US-Patent-6,765,190; US-Patent-Appl-SN-097699; US-Patent-Appl-SN-276568;
NASA-Case-LAR-16279-2; No Copyright; Avail: CASI; A02, Hardcopy
A multi-element optical detector system includes an electrically resistive screen that is substantially transparent to
radiation energy having a wavelength of interest. A plurality of electron transfer elements (e.g., a low work function
photoactive material or a carbon nanotube (CNT)-based element) are provided with each having a first end and a second end.
The first end of each element is spaced apart from the screen by an evacuated gap. When the radiation energy passes through
the screen with a bias voltage applied thereto, transfer of electrons through each element is induced from the first end to the
second end such that a quantity indicative of the electrons transferred through each element can be detected.
Author
Optical Equipment; Radiation Detectors; Electron Transfer
123