Ozone measurements in the mesosphere and stratosphere during two significant geophysical events
Ozone distribution measurements in mesosphere and stratosphere by rocket during seasonal ionospheric disturbance and solar eclipse
Hilsenrath, E.↗
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Positive holding of Schumann-type film for precise microdensitometry
Elastomer O ring vacuum device for positive holding of Schumann film for precise microdensitometry during rocket flight in 7 March 1970 solar eclipse
Hazen, N. L.↗
The shadow band phenomenon
Shadow band observations during 7 March 1970 solar eclipse, determining spectral energy distribution from magnetic tape recordings of collimated photocells output
Daly, C. J.↗
Photometric intensity and polarization measurements of the solar corona
Solar corona photometric intensity and polarization measurements during 1970 solar eclipse
Mcdougal, D. S.↗
Ionospheric storm of March 8, 1970
Electron content spatial and temporal variation during ionospheric storm of 8 March 1970 after total solar eclipse
Da Rosa, A. V.↗
The shadow band phenomenon.
Observation of shadow bands during the solar eclipse of Mar. 7, 1970. Data were gathered by recording onto magnetic tape of the output from six collimated photocells whose spectral responses ranged from the ultraviolet to the infrared, and by visual and mechanical measurement of the orientation and motion of the bands. The recorded data were later processed using the output from a frequency spectrum analyzer. Most of the energy of the shadow bands ranges between 1 and 25 Hz, and appears not unlike plots of scintillation spectra. The onset, amplitude, and duration of the shadow bands seem to be spectrally related to the limb darkening of the sun's photosphere. Other results of the experiment conclusively indicate that the shadow band phenomenon is a manifestation of atmospheric turbulence in the form of air packets of different density from that of their environment (density schlieren), made visible by the light from the crescent sun.
Quann, J. J.↗
The electromagnetic structure of interplanetary space
A method to calculate the three-dimensional structure of the interplanetary magnetic field is presented. The integrations are based on magnetograph recordings of longitudinal magnetic fields in the solar photosphere. The program by Altschuler and Newkirk is used to calculate the radial component of the magnetic field on the source surface, situated at r = 2.6r. This determines the inner boundary conditions for the integration outwards of the interplanetary field equations by means of the method that is described. Computer-drawn plots of the interplanetary field lines out to the earth's orbit are presented for the periods around the total solar eclipses of November 12, 1966, and March 7, 1970. During the former period the interplanetary field exhibited a clean, dipole-type structure, while during the latter period the field was more complicated and had four sectors in the equatorial plane. A movie was presented, showing how the interplanetary field structure rotates as seen by a magnetometer in the sun's equatorial plane.
Stenflo, J. O.↗
Large-scale solar magnetic fields and H-alpha patterns
Coronal and interplanetary magnetic fields computed from measurements of large-scale photospheric magnetic fields suffer from interruptions in day-to-day observations and the limitation of using only measurements made near the solar central meridian. Procedures were devised for inferring the lines of polarity reversal from H-alpha solar patrol photographs that map the same large-scale features found on Mt. Wilson magnetograms. These features may be monitored without interruption by combining observations from the global network of observatories associated with NOAA's Space Environment Services Center. The patterns of inferred magnetic fields may be followed accurately as far as 60 deg from central meridian. Such patterns will be used to improve predictions of coronal features during the next solar eclipse.
Mcintosh, P. S.↗
Recent results from satellite beacon measurements
A review is made of the techniques for measuring ionospheric electron content, the most important parameter in the study of transionospheric propagation. Data collected since 1964 have yielded a synoptic description of the behavior of the electron content in mid-latitudes. Empirical relationships between the level of solar activity and the electron content have been developed permitting the prognostication of the electron content values. Marked discrepancies between prognostication and observation which occur during ionospheric storms are being studied to identify their causes. Electron content bite-outs during solar eclipses fall off with distance from totality more rapidly than simple theory predicts suggesting the action of eclipse induced neutral winds. Gravity waves propagating in the thermosphere leave a signature in the electron content records. Studies of such records have allowed the identification of the position of the gravity wave source, and its radiation pattern.
Da Rosa, A. V.↗
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.↗
Measurement of stray radiance in the High Altitude Observatory's Skylab coronagraph
The paper outlines two techniques used for determining the instrumental stray radiance from orbital results obtained with the Skylab white light coronagraph. The first technique employs images of the lunar disk made near the time of solar eclipse to compare the apparent contrasts of maria and highlands recorded by the coronograph with those of previous studies and then determine the magnitude of the stray radiance and its variation along a radius. The second method determines the azimuthal variation of the stray radiance by measuring the change in the net radiance of a point in the coronal images as the image is rotated.
Csoeke-Poeckh, A.↗
CTS attenuation and cross-polarization measurements at 11.7 GHz
The results of data obtained 80 days preceding the solar eclipse shutdown of the CTS 11.7 GHz righthand circularly polarized beacon transmitter are presented. Attenuation and cross polarization isolation were measured. It was determined that depolarization presents a serious limitation to satellite system reliability when frequency reuse by polarization diversity is employed. A 27 db isolation margin would reduce reliability below 99.95%. For the same percentage the required fade margin was below 3 db.
Vogel, W. J.↗
Recent sounding rocket highlights and a concept for melding sounding rocket and space shuttle activities
Highlights include launching guided vehicles into the African Solar Eclipse, initiation of development of a Three-Stage Black Brant to explore the dayside polar cusp, large payload Aries Flights at White Sands Missile Range, and an active program with the Orion vehicle family using surplus motors. Sounding rocket philosophy and experience is being applied to the shuttle in a Get Away Special and Experiments of Opportunity Payloads Programs. In addition, an orbit selection and targeting software system to support shuttle pallet mounted experiments is under development.
Lane, J. H.↗
Winter nighttime ion temperatures and energetic electrons from OGO 6 plasma measurements
In the reported investigation, ion temperature and suprathermal electron flux data were acquired with the retarding potential analyzer on board the OGO 6 satellite when it was in solar eclipse. Attention is given to measurements in the 400- to 800-km height interval between midnight and predawn in the northern winter nonpolar ionosphere. Statistical analysis of data recorded during a 1 month time span permits a decoupling of horizontal and altitude effects. A distinct longitudinal variation is observed for ion temperature above 500 km, with a significant relative enhancement over the western North Atlantic. Altitude distributions of ion temperature are compatible with Millstone Hill profiles within the common region of this enhancement. Large fluxes of energetic electrons are observed and extend to much lower geomagnetic latitudes in the same longitude sector.
Sanatani, S.↗
High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution
SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.
Nussberger, A. A.↗
Lyman alpha coronagraph research sounding rocket program
The ultraviolet light coronagraph was developed and successfully flown on three rocket flights on 13 April 1979, 16 February 1980 and 20 July 1982. During each of these flights, the Ultraviolet Light Coronagraph was flown jointly with the White Light Coronagraph provided by the High Altitude Observatory. Ultraviolet diagnostic techniques and instrumentation for determining the basic plasma parameters of solar wind acceleration regions in the extended corona were developed and verified and the understanding of the physics of the corona through the performance, analysis and interpretation of solar observations advanced. Valuable UV diagnostics can be performed in the absence of a natural solar eclipse.
Parkinson, W. H.↗
The acoustic gravity wave induced by a point source in the middle atmosphere
Acoustic gravity wave (AGW) results computed for a stationary impulsive point source and a moving point source in the middle atmosphere are presented. For a stationary impulsive point Row's far field formula of the AGW was extended into the near field one, which comprises the Zeroth order Bessel function and its derivative terms. When (t-t sub o) is not large, the contribution of the derivative terms is important. The computed results agree with the experimental ones. For a moving point source with supersonic velocity, AGW is calculated using the moving point theory. Two solar eclipses that occurred in the lower latitude and over the ocean on Feb. 16, 1980, and June 11, 1983, were compared. The results show that the theoretical curve of AGW is fairly consistent with the observed ones.
Zhang, X. J.↗
International Ultraviolet Explorer (IUE) spacecraft battery performance update
January 26, 1987 marks the ninth inflight aniversary of the IUE spacecraft, launched into an eccentric synchronous orbit. The orbital path has subjected the spacecraft to 18 solar eclipse seasons since launch. Nine years of inflight operations culminate a major milestone for battery support to a spacecraft, which is well in excess of the initial 3 year design life. A brief outline of events, power system characteristics, and papers presented a previous battery workshops are provided. The IUE battery cell performance is excellent with the exception of the third electrode anomaly and temperature delta between batteries. Data indicates that battery depth-of-discharge (DOD) may be more critical to extend battery life than small operational temperature deltas between batteries. It is predicted that several additional years of battery life may be obtained by a reduction in operational battery DOD.
Tiller, Smith E.↗