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Monteith, J. H.

Publications and source records attributed to Monteith, J. H..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

IPLIB (Image processing library) user's manual

IPLIB is a collection of HP FORTRAN 77 subroutines and functions that facilitate the use of a COMTAL image processing system driven by an HP-1000 computer. It is intended for programmers who want to use the HP 1000 to drive the COMTAL Vision One/20 system. It is assumed that the programmer knows HP 1000 FORTRAN 77 or at least one FORTRAN dialect. It is also assumed that the programmer has some familiarity with the COMTAL Vision One/20 system.

Faulcon, N. D.↗
NASA NTRS1984

A comparison of two photogrammetric algorithms for the measurement of model deformation in the National Transonic Facility

A comparison was made of two photogrammetric measurement techniques which can be used for the determination of the spatial loctions of targets. One technique is known as the Direct Linear Transformation (DLT), and the other is referred to as the Bundle method. Each technique utilizes triangulation of image data from two or more cameras, but they differ in their method of determining camera parameters. While the study was performed with simulated data, the geometries, image data accuracies and other parameters were set to simulate conditions for a two-camera, photogrammetric system which will be used at the National Transonic Facility at the NASA's Langley Research Center. For the conditions studied the Bundle technique was found to have smaller errors. Both methods were sensitive to the spatial distribution of control-point targets, but this effected the accuracy of the Bundle algorithm less than that of the DLT algorithm.

Monteith, J. H.↗
NASA NTRS1982

Evaluation of an electro-optic remote displacement measuring system

An instrumentation system to provide a noncontact method for measurement of target positions was evaluated. The system employs two electro-optic camera units which give stereo information for use in determining three dimensional target locations. Specially developed, infrared sensitive photodetectors are used in the cameras to sense radiation from light emitting diode targets. Up to 30 of these targets can be monitored with a sampling rate of 312 Hz per target. An important part of the system is a minicomputer which is used to collect the camera data, sort it, make corrections for distortions in the electro-optic system, and perform the necesssary coordinate transformations. If target motions are restricted to locations in a plane which is perpendicular to a camera's optical axis, the system can be used with just one camera. Calibrations performed in this mode characterize accuracies in single camera operation. This information is also useful in determination of single camera contributions to total system errors. For this reason the system was tested in both the single camera and two camera (stereo) modes of operation.

Monteith, J. H.↗
NASA NTRS1978

An ultrasonic flowmeter for measuring dynamic liquid flow

A novel oscillating pipe system was developed to provide dynamic calibration wherein small sinusoidal signals with amplitudes of 0.5 to 10% of the steady-state flow were added to the steady-state flow by oscillating the flowmeter relative to the fixed pipes in the flow system. Excellent agreement was obtained between the dynamic velocities derived from an accelerometer mounted on the oscillating pipe system and those sensed by the flowmeter at frequencies of 7, 19, and 30 Hz. Also described were the signal processing techniques used to retrieve the small sinusoidal signals which were obscured by the fluid turbulence.

Carpini, T. D.↗
NASA NTRS1978

A computer-controlled instrumentation system for third octave analysis

An instrumentation system is described which employs a minicomputer, a one-third octave band analyzer, and a time code/tape search unit for the automatic control and analysis of third-octave data. With this system the information necessary for data adjustment is formatted in such a way as to eliminate much operator interface, thereby substantially reducing the probability for error. A description of a program for the calculation of effective perceived noise level from aircraft noise data is included as an example of how this system can be used.

Faulcon, N. D.↗
NASA NTRS1976

Measured response of a complex structure to supersonic turbulent boundary layers

Measurements of the response of a large frame-stringer panel excited by supersonic turbulent boundary layer are reported. The statistical description of the wall pressure fluctuations in terms of the mean flow parameters governing the turbulent boundary layer is given. These results can be used in the development of design criteria on the response of sidewall structure of a large airplane in supersonic flight, since both forcing field and structure are realistic. Results indicate the significant importance of the modal coupling and the acoustic damping. The acoustic damping plays a major role in the response of the structure.

Maestrello, L.↗