Engineering topics

Olsen, Robert O.

Publications and source records attributed to Olsen, Robert O..

3 records

NASA NTRS1993

Joint Acoustic Propagation Experiment (JAPE)

The Joint Acoustic Propagation Experiment (JAPE), performed under the auspices of NATO and the Acoustics Working Group, was conducted at White Sands Missile Range, New Mexico, USA, during the period 11-28 Jul. 1991. JAPE consisted of 220 trials using various acoustic sources including speakers, propane cannon, various types of military vehicles, helicopters, a 155mm howitzer, and static high explosives. Of primary importance to the performance of these tests was the intensive characterization of the atmosphere before and during the trials. Because of the wide range of interests on the part of the participants, JAPE was organized in such a manner to provide a broad cross section of test configurations. These included short and long range propagation from fixed and moving vehicles, terrain masking, and vehicle detection. A number of independent trials were also performed by individual participating agencies using the assets available during JAPE. These tests, while not documented in this report, provided substantial and important data to those groups. Perhaps the most significant feature of JAPE is the establishment of a permanent data base which can be used by not only the participants but by others interested in acoustics. A follow-on test was performed by NASA LaRC during the period 19-29 Aug. 1991 at the same location. These trials consisted of 59 overflights of supersonic aircraft in order to establish the relationship between atmospheric turbulence and the received sonic boom energy at the surface.

Carnes, Benny L.↗

NASA NTRS1993

Intercomparison of remote and balloon-borne sensors operated at JAPE-91

In recent years, there has been an increased availability of different types of remote sensors for measuring atmospheric parameters. With the introduction of remote sensors into field operation, questions have arisen as to their accuracy and precision. An attempt was made to address this issue by analyzing and intercomparing sets of wind and temperature data obtained during the Joint Acoustic Propagation Experiment (JAPE-9l) conducted at White Sands Missile Range, New Mexico, in Jul. and Aug. 1991. The remote sensing systems that were deployed included a 924 MHz wind profiler, two Doppler acoustic sodars, and a Radio Acoustic Sounding System (RASS). In situ measurements of wind, temperature, and humidity were also obtained from radiosondes. Individual system characteristics and the results of intercomparing the derived wind and temperature data from each of the systems are presented.

Okrasinski, Richard J.↗

NASA NTRS1990

A noise assessment and prediction system

A system has been designed to provide an assessment of noise levels that result from testing activities at Aberdeen Proving Ground, Md. The system receives meteorological data from surface stations and an upper air sounding system. The data from these systems are sent to a meteorological model, which provides forecasting conditions for up to three hours from the test time. The meteorological data are then used as input into an acoustic ray trace model which projects sound level contours onto a two-dimensional display of the surrounding area. This information is sent to the meteorological office for verification, as well as the range control office, and the environmental office. To evaluate the noise level predictions, a series of microphones are located off the reservation to receive the sound and transmit this information back to the central display unit. The computer models are modular allowing for a variety of models to be utilized and tested to achieve the best agreement with data. This technique of prediction and model validation will be used to improve the noise assessment system.

Olsen, Robert O.↗