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Muller, P. M.

Publications and source records attributed to Muller, P. M..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Users Guide to the JPL Doppler Gravity Database

Local gravity accelerations and gravimetry have been determined directly from spacecraft Doppler tracking data near the Moon and various planets by the Jet Propulsion Laboratory. Researchers in many fields have an interest in planet-wide global gravimetric mapping and its applications. Many of them use their own computers in support of their studies and would benefit from being able to directly manipulate these gravity data for inclusion in their own modeling computations. Pubication of some 150 Apollo 15 subsatellite low-altitude, high-resolution, single-orbit data sets is covered. The doppler residuals with a determination of the derivative function providing line-of-sight-gravity are both listed and plotted (on microfilm), and can be ordered in computer readable forms (tape and floppy disk). The form and format of this database as well as the methods of data reduction are explained and referenced. A skeleton computer program is provided which can be modified to support re-reductions and re-formatted presentations suitable to a wide variety of research needs undertaken on mainframe or PC class microcomputers.

Muller, P. M.↗
NASA NTRS1980

Observations of a probable change in the solar radius between 1715 and 1979

A decrease in the solar radius is determined using the technique of Dunham and Dunham (1973), in which timed observations are made just inside the path edges. When the method is applied to the solar eclipses of 1715, 1976, and 1979, the solar radius for 1715 is 0.34 + or - 0.2 arc second larger than the recent values, with no significant change between 1976 and 1979. The duration of totality is examined as a function of distance from the edges of the path. Corrections to the radius of the sun derived from observations of the 1976 and 1979 eclipses by the International Occultation Timing Association are also presented.

Dunham, D. W.↗
NASA NTRS1976

Determination of the cosmological rate of change of G and the tidal accelerations of earth and moon from ancient and modern astronomical data

The theory and numerical analysis of ancient astronomical observations (1374 to 1715) are combined with modern data in a simultaneous solution for: the tidal acceleration of the lunar longitude; the observed apparent acceleration of the earth's rotation; the true nontidal geophysical part of this acceleration; and the rate of change in the gravitational constant. Provided are three independent determinations of a rate of change of G consistent with the Hubble Constant and a near zero nontidal rotational acceleration of the earth. The tidal accelerations are shown to have remained constant during the historical period within uncertainties. Ancient and modern solar system data, and extragalactic observations provided a completely consistent astronomical and cosmological scheme.

Muller, P. M.↗
NASA NTRS1975

The accelerations of the earth and moon from early astronomical observations

An investigation has compiled a very large amount of data on central or near central solar eclipses as recorded in four principal ancient sources (Greek and Roman classics, medieval European chronicles, Chinese annals and astronomical treatises, and Late Babylonian astronomical texts) and applied careful data selectivity criteria and statistical methods to obtain reliable dates, magnitudes, and places of observation of the events, and thereby made estimates of the earth acceleration and lunar acceleration. The basic conclusion is that the lunar acceleration and both tidal and nontidal earth accelerations have been essentially constant during the period from 1375 B.C. to the present.

Muller, P. M.↗
NASA NTRS1974

Lunar gravity - Apollo 15 Doppler radio tracking

Analysis and interpretation of the lunar gravity measurements obtained from Apollo 15 Doppler radio tracking data. The extent of surface coverage was limited to the trajectory paths of the command and service module during revolutions 3 through 11, when it was at a relatively low periapsis altitude just prior to undocking with the lunar module. The trajectory was close to the most optimal for study of the details of the Serenitatis and Crisium mascons. The periapsis altitude was about 12 km at the center of Mare Serenitatis, one of the largest mascons, and the one in the most favorable viewing geometry. The results obtained strengthen Booker's (1970) contention that all mascons have approximately the same thickness.

Muller, P. M.↗
NASA NTRS1973

Three-D multilateration: A precision geodetic measurement system

A technique of satellite geodesy for determining the relative three dimensional coordinates of ground stations within one centimeter over baselines of 20 to 10,000 kilometers is discussed. The system is referred to as 3-D Multilateration and has applications in earthquake hazard assessment, precision surveying, plate tectonics, and orbital mechanics. The accuracy is obtained by using pulsed lasers to obtain simultaneous slant ranges between several ground stations and a moving retroreflector with known trajectory for aiming the lasers.

Escobal, P. R.↗
NASA NTRS1972

A 3-D Multilateration: A Precision Geodetic Measurement System

A system was designed with the capability of determining 1-cm accuracy station positions in three dimensions using pulsed laser earth satellite tracking stations coupled with strictly geometric data reduction. With this high accuracy, several crucial geodetic applications become possible, including earthquake hazards assessment, precision surveying, plate tectonics, and orbital determination.

Escobal, P. R.↗
NASA NTRS1972

Possible variation of the gravitational constant over the elements.

We re-examine the theory and data of the Kreuzer experiment to measure the relative difference in the gravitational constant between two elements. Significant errors appear in the statistical analysis of Kreuzer which vitiate his conclusions. The upper bound for the relative difference of F and Br from his experimental data correctly becomes .02, about 10 times the limit already set on the general variation of the gravitational constant over the elements by direct use of a Cavendish balance.

Gilvarry, J. J.↗
NASA NTRS1972

A proposed lunar orbiting gravity gradiometer experiment.

Analysis of the gravity gradiometer developed by Forward and Bell (1970) suggest that an accuracy, in the range 0.1 to 0.5 EU can be expected in a lunar orbiter application. This accuracy will allow gradient anomalies associated with mascons to be mapped with 1% accuracy and should reveal a great deal of new information about the lunar gravity field. The proposed experiment calls for putting such a gradiometer into a closely circular polar orbit at an average height of about 30 km above the lunar surface. This orbit allows the entire lunar surface to be covered in fourteen days, the gradiometer to be checked twice per revolution and results in successive passes above the lunar surface being spaced at about the resolution limit of about 30 km set both by the satellite altitude and instrumental integration time.

Debra, D. B.↗
NASA NTRS1972

Lunar gravity via Apollo 14 Doppler radio tracking.

Gravity measurements at high resolution were obtained over a 100-kilometer band from +70 to -70 deg of longitude during the orbits of low periapsis altitude (approximately 16 kilometers). The line-of-sight accelerations are plotted on Aeronautical Chart and Information Center mercator charts (scale 1:1,000,000) as contours at 10-milligal intervals. Direct correlations between gravity variations and surface features are easily determined. Theophilus, Hipparchus, and Ptolemaeus are negative features, whereas Mare Nectaris is a large positive region. The acceleration profiles over Mare Nectaris are suggestive of a broad disk near the surface rather than a deeply buried spherical body.

Sjogren, W. L.↗
NASA NTRS1972

S-band transponder experiment

The experiment which derives data from three lunar-orbiting objects, the command-service module (CSM), the lunar module (LM), and the subsatellite in the S-band is described. Each provides detailed information on the near-side lunar gravitational field. The primary emphasis is on the low-altitude (20 km) CSM data. The LM data cover a very short time span and are somewhat redundant with the CSM data. The resolution of the high-altitude (100 km) CSM data is not as great as that of the low altitude data. The low-altitude CSM and LM data coverage and the complementary coverage obtained during the Apollo 14 mission are presented. The experiment uses the same technique of gravity determination employed on the Lunar Orbiter, in the data of which the large anomalies called mascons were first observed. The data consist of variations in the spacecraft speed as measured by the Earth-based radio tracking system.

Sjogren, W. L.↗
NASA NTRS1972

S band transponder experiment

It is reported that this experiment measures the lunar gravitational field, which in turn provides information on the distribution of lunar mass and its correlation with surface features such as craters, mountains, and maria. The lunar gravitational field is measured by observing the dynamical motion of spacecraft in free-fall orbits. Effective detection of mass variations is greatly enhanced by low-altitude trajectories, such as the eccentric orbits during revolutions 3 to 16 of the Apollo 16 spacecraft and the 11 km periapsis of the Apollo 16 subsatellite during May 1972. The observational data are the precise earth-based radio tracking measurements initially used for real-time navigation.

Sjogren, W. L.↗