Satellite observations of band-limited micropulsations during a magnetospheric substorm
Band limited micropulsations observed in space during magnetospheric substorm by fluxgate magnetometer on OGO 5
Coleman, P. J., Jr.↗
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Magnetic field and electron observations near the dawn magnetopause
Magnetic field and electron plasma observations near dawn magnetopause by triaxial spectrometer and fluxgate magnetometer on satellite OGO 5
Ogilvie, K. W.↗
Asymmetric ring current at twilight local time
OGO-2 rubidium vapor magnetometer measurements comparison with surface magnetic observatory data during geomagnetic storms, considering asymmetric ring current
Langel, R. A.↗
The magnetism of the moon
Lunar magnetic fields measured by magnetometers placed by Apollo 12 and 14 astronauts, considering permanent fields due to fossil magnetic material and transient fields
Dyal, P.↗
Rocket measurements of the magnetic fields associated with visual aurorae
Electrojet currents association with visible aurorae, using sounding rockets with rubidium vapor magnetometers
Burrows, K.↗
Dynamics of the solar wind and its interaction with bodies in the solar system
A discussion of the solar wind and its interaction with bodies of the solar system is presented. An overall unified account of the role of shock waves in the heating of the solar corona, the transmission of solar disturbances to the solar system, the flow fields of planets and natural satellites, and biological effects are provided. An analysis of magnetometer data from Explorer 33 and Vela 3A satellites to identify characteristics of solar wind shock waves is included.
Spreiter, J. R.↗
A study of the electromagnetic interaction between planetary bodies and the solar wind
Theoretical and computational techniques were developed for calculating the time dependent electromagnetic response of a radially inhomogeneous moon. The techniques were used to analyze the experimental data from the LSM (lunar surface magnetometer) thus providing an in-depth diagnostic of the Lunar interior. The theory was also incorporated into an existing computer code designed to calculate the thermal evolution of planetary bodies. The program will provide a tool for examining the effect of heating from the TE mode (poloidal magnetic field) as well as the TM mode (toroidal magnetic field).
Schwartz, K.↗
Ionospheric nf sub H resonances: Frequency shifts versus plasma conditions
The Alouette 2 resonances observed near the harmonics of the electron cyclotron frequency f sub H reveal frequency shifts (relative to the n(f sub H) values derived from model field calculations) which can be interpreted in terms of plasma wave dispersion effects. These effects are observed on the 2(f sub H) resonance when it is near the resonance observed close to the upper hybrid frequency f sub T. The observations suggest that an oblique echo model may be required to give a proper interpretation of the 2(f sub H) resonance. Cyclotron damping can be ignored only when the angle between the propagation vector and the direction perpendicular to the earth's magnetic field B is less than a few degrees for the 2(f sub H) wave, and less than a few tenths of a degree for the n(f sub H) waves with n 2. The negative offset of the absolute value of B inferred from the plasma resonance observations is consistent with expectations based on recent OGO 3 and OGO 5 rubidium magnetometer observations at higher altitudes in the equatorial regions.
Benson, R. F.↗
Observations of earth eigen vibrations possibly excited by low frequency gravity waves
A cryogenic gravity meter made of two parts, a magnetic suspension unit and a detection module, was used to monitor earth eigen vibrations. The magnetic field and field gradient are generated by energizing a set of superconducting coils made of niobium-zirconium alloy wire. The detection module is a double Josephson junction magnetometer. The output is printed on a chart recorder and later digitized using a computer; a Fourier transformation is performed on the accumulated data. The measurements of eigen vibrations are summarized in tabular and graphical representations.
Tuman, V. S.↗
Mission definition study for Stanford relativity satellite. Volume 1: Systems and program
The objective of the relativity satellite mission is to perform an experiment in which a gyroscope in motion about the earth undergoes precession, presumably relativistic, with respect to the fixed stars. Performance of this experiment would clearly test the general theory of relativity and its various modifications. This is the only experiment suggested to date which would confirm the existence of motional drift as well. A mission is defined in which the measurement of the geodetic effect term to 0.2 arc sec/yr is achievable and the measurement of both geodetic and motional drift terms to an accuracy of 0.001 arc sec/yr may be possible. The design of the flying dewar satellite needed to maintain the experiment at cryogenic temperatures is discussed. The gyroscopes, magnetometer, and optical contacting method for dimensional stability of the experimental assembly are considered.
Source record↗
Interplanetary magnetic sector polarity inferred from polar geomagnetic field observations
In order to infer the interplanetary sector polarity from polar geomagnetic field diurnal variations, measurements were carried out at Godhavn and Thule (Denmark) Geomagnetic Observatories. The inferred interplanetary sector polarity was compared with the polarity observed at the same time by Explorer 33 and 35 magnetometers. It is shown that the polarity (toward or away from the sun) of the interplanetary magnetic field can be reliably inferred from observations of the polar cap geomagnetic fields.
Friis-Christensen, E.↗
Mariner-Venus 1967
Detailed information on the spacecraft performance, mission operations, and tracking and data acquisition is presented for the Mariner Venus 1967 and Mariner Venus 1967 extension projects. Scientific and engineering results and conclusions are discussed, and include the scientific mission, encounter with Venus, observations near Earth, and cruise phase of the mission. Flight path analysis, spacecraft subsystems, and mission-related hardware and computer program development are covered. The scientific experiments carried by Mariner 5 were ultraviolet photometer, solar plasma probe, helium magnetometer, trapped radiation detector, S-band radio occultation, dual-frequency radio propagation, and celestial mechanics. The engineering experience gained by converting a space Mariner Mars 1964 spacecraft into one flown to Venus is also described.
Source record↗
SAS-A spacecraft magnetic tests
Magnetic tests were conducted on the spacecraft for: (1) alignment, compensation, calibration, and bias determination for the spacecraft three-axis vector magnetometer; (2) determination of permanent, induced, and stray magnetic moments of the spacecraft and compensation of permanent magnetic moments by permanent magnets; and (3) evaluation of the spin and attitude control system.
Boyle, J. C.↗
Saturation magnetization of polycrystalline iron
The magnetic moment per gram, sigma (H sub I, T), where H sub I is the internal field and T is the temperature, was measured for a polycrystalline iron sphere with the vibrating-sample magnetometer. The instrument was calibrated by using a method utilizing the high permeability of an iron sphere. The spontaneous moment, sigma(0, T),was obtained from plots of sigma(H sub I, T) as a function of H sub I for temperatures from 4.2 K to room temperature. The value of the spontaneous moment, sigma(0, T), at 298.9 K was 217.5 + or -0.4 emu/g. The extrapolated moment, sigma(0, 0),at absolute zero from a plot of sigma(0, T) as a function of T to 3/2 power was 221.7 + or - 0.4 emu/g.
Behrendt, D. R.↗
Search for magnetic monopoles in the moon
A search was made for the possible existence of magnetic monopoles on the moon using magnetic observations from magnetometer experiments on Explorer 33 and 35. A series of 37 orbital plots were analyzed and it was determined that the net number of magnetic monopoles was less than 1 per 10 to the 7th power cc. This is equivalent to the difference in the number of northern and southern magnetic monopoles within the moon being less than 1 per 10 to the 31st power nucleons. Searches for monopoles from lunar samples have also proven negative.
Schatten, K. H.↗
Study on multi-satellite, multi-measurement of the structure of the earth's bow shock
The pulsation model of the earth's bow shock proposed a nonuniform shock having both perpendicular (abrupt, monotonic) and oblique (oscillatory, multigradient) properties simultaneously, depending on local orientation of the shock surface to the interplanetary field B sub sw in parallel planes defined by B sub sw and solar wind velocity. Multiple, concurrent, satellite observations of the shock and solar wind conditions were used. Twenty-six potentially useful intervals of concurrent Explorer 33 and 35 data acquisition were examined, of which six were selected for closer study. In addition, two years of OGO-5 and HEOS 1 magnetometer data were examined for possible conjunctions to these spacecraft having applicable data. One case of clear nonuniformity and several of field-dependent structure were documented. A computational aid, called pulsation index, was developed.
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Frequency dependence of ATS-1 observed micropulsations of some geophysical parameters
Low frequency oscillations in the earth's magnetic field at the synchronous orbit were observed with the magnetometer experiment on board the ATS 1 satellite since Dec. 1966. An analysis of oscillations in the range .002 f .02 H3 for the interval Dec. 1966 through Dec. 1968 is reported. It was found that the frequency of an event increases with the sum of Kp for 24 hours prior to the event midpoint. For events with duration greater than 6 hours, the product moment correlation coefficient for frequency f, and the sum Kp was R = 0.87. The best least squares linear fit to the data for these events was f = (0.32) sum Kp = 5.1. For the same events the correlation coefficient for frequency and Dst was R = -0.83.
Mason, F.↗
Spectral and polarization analysis of micropulsations observed at ATS-1
Results are reported for an analysis of low frequency oscillations in the earth's magnetic field as observed at the synchronous orbit by the magnetometer experiment on board ATS 1. Oscillations in the range .002 f .02 H3 for the period Dec. 1966 through Dec. 1967 were studied. The analysis combines a detailed, computer-processed, spectral analysis of selected events with a less detailed manual analysis of all events in the two year time interval from Dec. 1966 to Dec. 1968. The computer analysis revealed that a given event is often characterized by a dominat, narrow, spectral peak whose associated oscillations are almost entirely limited to a plane, together with several minor peaks. Dynamic spectral analyses revealed that minor spectral peaks appear as short isolated bursts. The sense of rotation of the perturbation vector tends to change from right-handed elliptical at the beginning of a burst to left-handed elliptical at the end. The major axis of the polarization ellipse is inclined by typically 30 deg east of radial.
Morris, W.↗