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Nimbus 4 satellite data for the period September 1 through October 31 1970 are presented. Data are also given on interrogation recording and location system balloon tracking from launch through March 27, 1971.
An analytical investigation was conducted on the experimental technique that uses shielding by an acoustically hard baffle to determine the location of noise sources in a jet. The jet exhausts through a circular hole in the baffle and the radiated acoustic power is considered to be generated by a distributed source along the jet axis. It is found that the effect of the baffle on the radiated power can be neglected only when the size of the source is on the order of a wavelength of the emitted sound or larger. Since noise sources in a jet are compact, the experimental technique is insufficient to identify these sources.
A technique is presented for dealing with the problem of an elastic domain containing an arbitrarily oriented internal crack. The problem is formulated as a system of integral equations for a fictitious layer of body forces imbedded in the plane along a closed smooth curve encircling the original domain. The problems of a half plane with a crack in the neighborhood of its free boundary and of an infinite strip containing a symmetrically located internal crack with an arbitrary orientation are considered as examples. In each case the stress intensity factors are computed and are given as functions of the crack angle.
Data were obtained concerning a model which utilized a two-dimensional sonic jet. It was found that outflow and jet location significantly influence the magnitude and behavior of the secondary jet interaction forces. Continued refinements in jet interaction analyses which do not account for outflow are of limited usefulness in the design of control systems for supersonic and hypersonic vehicles. The jet total back pressure ratio increases with either jet pressure ratio or freestream Mach number.
Description of an approximate method for predicting the pressure in the immediate corner region and the shock structure on stream-aligned, sharp-leading-edge, symmetrical corner configurations. The method is basically the two-shock method developed by Charwat and Redekopp (1966), with the additional assumption that the corner fillet shock can be located from the calculated pressure in the corner. Corner pressures are correlated over a wide range of Mach numbers in air and helium for different corner wedge angles. The shock structure calculated by this method is compared with supersonic and hypersonic data.
Satellite location and data collection systems development began in the early 1960's in NASA and the French CNES. These systems were initially developed for application to meteorology and oceanography as a means of tracking moving platforms on a global scale. Additional applications such as geology, hydrology, and ecology have since evolved. To date, five successful missions have been completed. With each successive launch, systems improved in accordance with user requirements - particularly reduction in cost and complexity of platform equipment. With planned launches, facilities will be available to the user community through 1980; NASA is currently forecasting needs beyond 1980.
Ultraviolet photographs of the earth made from the moon on the Apollo 16 mission showed two bands of emission extending from the evening terminator to the limb. The location in magnetic latitude and local time of these bands is consistent with a mechanism involving radiative recombination of O(+) ions in the F2 region of the ionosphere.
Program combines all calculation and determination requirements into one comprehensible technique. Program automatically performs selection of separation springs, composition of spring sets, and correct spring location with improved accuracy and reliability.
Detector includes delay lines connected to each detector surface strip. When several particles strike different strips simultaneously, pulses generated by each strip are time delayed by certain intervals. Delay time for each strip is known. By observing time delay in pulse, it is possible to locate strip that is struck by particle.
A theoretical framework for evaluating the effects of introducing new transportation on residential travel patterns is presented. Data are based on changes in residential location of urban commuters that alter the mode and length of work trips as well as economic factors.
The author has identified the following significant results. Hydrologic inventories, throughout the year, were made in interior basins that have not been measured previously because of their inaccessibility. Interior basins during the last ERTS-1 year (August 1972 to August 1973) had driest ground conditions in late September 1972 and had wettest ground conditions from March through May 1973, depending upon location. Bearing strengths of playa soils can be inferred from the changing hydrologic conditions through the seasons as recorded by ERTS-1, with prior ground control. Slight differences in salt-crust morphology and in moisture contest of playa soils can be greatly enhanced by rationing and stretching techniques. Differences in water area and silt content can be enhanced by using a three-stage photographic masking technique employing bands 4, 5, and 7.
The author has identified the following significant results. Possible geologic structures in the basin sediments of Carbon County and vicinity were located by interpretation of ERTS-1 imagery. These same structures are not evident on existing conventional geologic maps of the area. Subsequent field checks confirmed much of the geologic interpretation, but revealed that two apparent closed structures identified on the ERTS-1 imagery were actually topographic pseudostructures in flat or homoclinal sediments. Stereoscopic coverage (where available) allows the interpreter to avoid such misinterpretations.
A method is described for finding the location of a curved line in space from local azimuth as a function of elevation data obtained at several observation sites. A least-squares criterion is used to insure the best fit to the data. The method is applicable to the triangulation of an object having no identifiable structural features, provided its width is very small compared with its length so as to approximate a line in space. The method was implemented with a digital computer program and was successfully applied to data obtained from photographs of a barium ion cloud which traced out the earth's magnetic field line at very high altitudes.
The lane ambiguity problem prevents the utilization of the Omega system for many applications such as locating buoys and balloons. The method of multiple lines of position introduced herein uses signals from four or more Omega stations for ambiguity resolution. The coordinates of the candidate points are determined first through the use of the Newton iterative procedure. Subsequently, a likelihood function is generated for each point, and the ambiguity is resolved by selecting the most likely point. The method was tested through simulation.
System fixes location of charge buildup in clouds. It provides range, azimuth, and elevation in real-time so that warning of charge buildup can be implemented.
The effects of various propulsion system parameters on the characteristics of a supersonic transport were investigated. The effects of arbitrarily scaling engine size on wave drag, friction drag, drag-due-to-lift, wing sizing, airplane balance, and airplane weight were studied. These evaluations were made for two families of nacelle shapes, resulting from typical turbojet and turbofan installations. Also examined were effects of nacelle location, and the wing camber plane deformations required to cancel the nacelle interference pressure field at cruise Mach number (2.7 M) were determined. The most drag-sensitive parameter is found to be nacelle shape. Similarly, wing deformation requirements are found to be primarily affected by nacelle shape. Effects of engine size variations are noted primarily in airplane gross weight.
The FLAIR system, as now produced, automatically updates each vehicle's location and corresponding officer's status once each two seconds and presents this information to police dispatchers in the command and control center. The position of all vehicles available for assignment is displayed on a color video map at each dispatcher's console to an accuracy of 50 feet. This gives the dispatcher a continuous picture of the deployment of the total available force and thus complete command and control of all police under his responsibility.
A series of static tests were conducted on a model fan with a diameter of 14.0 cm to determine the fan operating characteristics, the inlet static pressure contours, the fan-exit total and static pressure contours, and the fan-exit pressure distortion parameters associated with the installation of a partial-circumferential-emission cascade thrust reverser. The tests variables included the cascade axial length, the axial location of the reverser, and the type of fan inlet. It was shown that significant total and static pressure distortions were produced in the fan aft duct, and that some configurations induced a static pressure distortion at the fan face. The amount of flow passed by the fan and the level of the flow distortions were dependent upon all the variables tested.