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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Identification of satellites possibly active during the IMS and their orbital configurations

A survey has been made to identify presently operating as well as planned spacecraft which may contribute measurements of the magnetosphere or interplanetary medium during the IMS. The total set consists of 25 scientific earth-orbiting, 9 heliocentric, and 17 communication, navigation or meteorological spacecraft, which carry environmental monitoring experiments. The orbital elements of each are displayed. In addition, techniques for the display of positions in various orbits are presented to illustrate how interesting configurations can be determined during the IMS. The positions of presently orbiting heliocentric spacecraft are shown at various intervals with respect to the nominal interplanetary magnetic field spiral and the earth. Plots of the latest ISEE-A orbit in solar magnetospheric co-ordinates are presented to determine neutral-sheet crossing.

Vette, J. I.↗
NASA NTRS1982

Pulsation research during the IMS

After describing the development status of the field of magnetic pulsations in 1975, before the initiation of the International Magnetospheric Study (IMS), attention is given to the IMS's novel observational results and an attempt is made to identify the most effective research methods employed. It is found that the most fruitful work involved small-scale collaboration between a few individuals or a few groups possessing complementary data sets. Consideration is restricted to research on the long period pulsations which can be broadly classified as field line resonances. Recommendations are made for future research efforts.

Hughes, W. J.↗
NASA NTRS1982

Data from ISEE-3 for the IMS period

The International Sun-Earth Explorer (ISEE) Project represents a joint effort between the European Space Agency and NASA. The primary objective of the project is the study of the outer magnetosphere. A review is presented concerning the data available from ISEE-3 up to the end of the International Magnetospheric Study (IMS) period (December 31, 1979), taking into account the approaches used to obtain the data. Attention is given to the ISEE-3 as an upstream monitor, ISEE-3 an an observer of the magnetosphere, aspects of ISEE-3 data availability, questions regarding the data link, and the definitive orbit position of ISEE-3 throughout the IMS.

Von Rosenvinge, T. T.↗
NASA NTRS1990

Coordinated optical and ultraviolet observations of IM Pegasi

IUE spectra and optical observations of IM Peg obtained during the summers of 1985 and 1986 are analyzed. The modulations of the UV emission lines and the H-alpha, H-beta, and the CaII IR triplet (IRT) optical lines are examined. It is observed that: the UV emissin-line modulation increases as a function of height, H-alpha variability is related to stochastic events, H-beta displays excess absorption relative to a standard star, and the Ca IRT reveals a clear modulation with phase. It is noted that IM Peg corresponds to the solar paradigm used to explain RS CVn activity.

Huenemoerder, David P.↗
NASA NTRS1995

Application of Ion Mobility Spectrometry (IMS) in forensic chemistry and toxicology with focus on biological matrices

The IMS (Ion Mobility Spectroscopy) instrument 'Ionscan' takes advantage of the fact that trace quantities of illicit drugs are adsorbed on dust particles on clothes, in cars and on other items of evidence. The dust particles are collected on a membrane filter by a special attachment on a vacuum cleaner. The sample is then directly inserted into the spectrometer and can be analyzed immediately. We show casework applications of a forensic chemistry and toxicology laboratory. One new application of IMS in forensic chemistry is the detection of psilocybin in dried mushrooms without any further sample preparation.

Bernhard, Werner↗
NASA NTRS2010

Plasma IMS Composition Measurements for Europa and Ganymede

NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4n surface composition to trace elemental [1] and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged.

Sittler, E.↗
NASA NTRS2015

Regional and Global Atmospheric CO2 Measurements Using 1.57 Micron IM-CW Lidar

Atmospheric CO2 is a critical forcing for the Earth's climate, and knowledge of its distribution and variations influences predictions of the Earth's future climate. Accurate observations of atmospheric CO2 are also crucial to improving our understanding of CO2 sources, sinks and transports. To meet these science needs, NASA is developing technologies for the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission, which is aimed at global CO2 observations. Meanwhile an airborne investigation of atmospheric CO2 distributions as part of the NASA Suborbital Atmospheric Carbon and Transport â€" America (ACT-America) mission will be conducted with lidar and in situ instrumentation over the central and eastern United States during all four seasons and under a wide range of meteorological conditions. In preparing for the ASCENDS mission, NASA Langley Research Center and Exelis Inc./Harris Corp. have jointly developed and demonstrated the capability of atmospheric CO2 column measurements with an intensity-modulated continuous-wave (IM-CW) lidar. Since 2005, a total of 14 flight campaigns have been conducted. A measurement precision of approx.0.3 ppmv for a 10-s average over desert and vegetated surfaces has been achieved, and the lidar CO2 measurements also agree well with in-situ observations. Significant atmospheric CO2 variations on various spatiotemporal scales have been observed during these campaigns. For example, around 10-ppm CO2 changes were found within free troposphere in a region of about 200A-300 sq km over Iowa during a summer 2014 flight. Results from recent flight campaigns are presented in this paper. The ability to achieve the science objectives of the ASCENDS mission with an IM-CW lidar is also discussed in this paper, along with the plans for the ACT-America aircraft investigation that begins in the winter of 2016.

Lin, Bing↗
NASA NTRS1975

IMS/Satellite Situation Center report. Special IMS periods for 1976

Special International Magnetospheric Study (IMS) Satellite Periods selected at times when two or more satellites are expected to be in interesting regions of the magnetosphere simultaneously are described. Data are presented to aid in defining a program of magnetospheric observations which emphasizes coordinated measurements of satellites, rockets, balloons, aircraft, and ground-based stations. The position is given of currently operating high altitude spacecraft in the Geocentric Solar Ecliptic, Geocentric Solar Magnetospheric, and Solar Magnetic coordinate systems to determine their passage through the bow shock, the magnetopause, the cusp, or the neutral sheet region. Information on the synchronous and low altitude spacecraft and experiments are included in tabular form along with a tabular summary of all the rocket, balloon, and aircraft campaigns in 1976.

Source record↗
NASA NTRS1976

Daily summary for IMS high-altitude satellites, days 1-181 1977

A description of the orbital positions is provided for a number of high altitude satellites capable of making magnetospheric measurements in the first half of 1977 as part of the International Magnetospheric Study (IMS). Six artificial satellites -- Vela 5B, IMP-H, IMP-J, Solrad 11A, Solrad 11B, and Hawkeye 1 -- have been chosen along with the moon. The daily position summary of the satellites includes data tables which provide the crossing times of the bow shock and magnetopause, as well as the entry and exit times from the cusp, the high latitude tail, the midlatitude tail, and the neutral sheet region.

Source record↗
NASA NTRS1977

The IMS Satellite Situation Center

Following a brief historical review of the SSC (Satellite Situation Center), created by the U.S. for the IMS (International Magnetospheric Study), its main functions are discussed. The services of the SSC include the accurate orbit determination of the satellites, 12-18 months in advance and the coordination of simultaneous observations by a multispacecraft system, which are essential for the optimization of the scientific gains from experiments conducted with limited resources. For 1976 SSC generated plots of the satellites Vela 5B, Vela 6A, Vela 6B, Hawkeye 1, Imp H (7), Imp J (8) by computing certain projections of the solar ecliptic, solar magnetospheric, and solar magnetic coordinate systems. The SSC system was automated by the addition of a computer system capable of interactive graphics. The SSC can also provide the ground-based campaigns with a graphical or tabular information about the position low-altitude satellites in any coordinate system. The possible participation of the SSC in future Electrodynamics Explorer mission, Space Shuttle programs is also being explored.

Sugiura, M.↗
NASA NTRS1982

Overview of the IMS July 29, 1977, magnetic storm analysis

The physical characteristics and temporal development of a significant IMS magnetospheric event - the sudden commencement and multiple substorms of July 29, 1977 - are reviewed. It is pointed out that the ring current showed a maximum at 0600 UT and a major perturbation at 1230 UT, corresponding to the last substorm. The computerized coordinated data analysis workshop (CDAW 2) conducted in October 1979 is described. Attention is given to the solar wind conditions and magnetospheric response.

Manka, R. H.↗
NASA NTRS1982

Availability of IMP-7 and IMP-8 data for the IMS period

The relation of IMP-7 and IMP-8 data to the International Magnetospheric Study is discussed. Relevant spacecraft and experiment characteristics, and the nature and accessibility of data from each experiment, are identified. Finally the potential value of IMP data in IMS studies is illustrated with a few citations from the IMP Bibliography and with figures from a recent multiple-data-set magnetotail plasma sheet study.

King, J. H.↗
NASA NTRS1982

Atmosphere explorer and the IMS

The Atmosphere Explorer (AE) program provided assistance to participants in the International Magnetosphere Study (IMS). The AE program, which began about 1970 employed three spacecraft in three complementary orbits. The program initiated a concept of a common data base, which is, a data base shared by all the participating investigators, to facilitate the correlation of the measured parameters. The immediate goal of the AE program has been study of the thermosphere, giving particular attention to photochemistry. Three satellites, AE-C, D, and E, were launched into orbits of 68 deg, 90 deg, and 19 deg inclination respectively in December 1973, October 1975, and November 1975. An instrument complement description is provided, and the AE data base is discussed.

Spencer, N. W.↗
NASA NTRS1984

A case-study of the evolution of polar-cap currents and auroral electrojets during polar geomagnetic disturbances with IMS magnetometer data

The development of the polar cap current and the relationship of that development to the evolution of auroral electrojets during individual polar geomagnetic disturbances is studied using 1 min average data from US-Canada IMS network stations and standard magnetograms from sites on the polar cap and in the auroral zone. It is found that even when the auroral electrojet activity is weak, polar cap currents producing fields of magnitude approximately 100-200 nT almost always exist. A normal convection current system exists quasi-persistently in the polar cap during extended quiet or weakly disturbed periods of auroral electrojet activity. After one such period, some drastic changes occur in the polar cap currents, which are followed by phases of growth, expansion, and recovery. Polar cap currents cannot all be completely ascribed to a single source mechanism.

Iijima, T.↗
NASA NTRS1986

The ultraviolet spectrum of the eclipsing binary IM Aurigae

Low dispersion IUE spectra have been obtained at primary and secondary minima, together with a high dispersion spectrum near maximum, for the eclipsing Algol-type IM Aurigae system. The weak, sharp absorption features noted at two distinct velocities in the high dispersion data are attributed to circumbinary gaseous shells and/or gas streams between the stellar components. The implications of these results for the recently observed increase in O-C values of the primary minimum, which prompted this UV spectral search for evidence of a recent mass-loss event, are discussed.

Bruhweiler, F. C.↗
NASA NTRS1987

A flare event of the long-period RS Canum Venaticorum system IM Pegasi

The characteristics of a flare event detected on the long-period RS CVn system IM Pegasi are reported. The low-resolution spectrum show enhancements of up to a factor of five in some emission lines. All of the ultraviolet emission lines normally visible are enhanced significantly more than the normal 30 rotational modulation. Emission fluxes of both the quiescent and flare event are used to construct models of the density and temperature variation with height. These models reveal a downward shift of the transition region during the flare. Scaled models of the quiet and flaring solar outer atmosphere are used to estimate the filling factor of the flare event at about 30 percent of the stellar surface. The pattern of line enhancements in the flare is the same as a previous event in Lambda Andromeda observed previously.

Buzasi, Derek L.↗
NASA NTRS1990

Cometary ion flow variations at Comet P/Halley as observed by the Giotto IMS experiment

The moments of the cometary-ion distributions are determined through a three-dimensional analysis of the Giotto IMS high-intensity spectrometer (HIS) data. The spectrometer is described, with emphasis on its angle analyzer and mass analyzer. The method of data analysis is outlined, with ion-flow vectors and temperatures being addressed. The results of the water group ion-flow profile are presented, and it is noted that, after crossing the cometopause region, the ions become gradually colder. At cometocentric distances larger than 130,000 km, the cometary-ion temperature is found to be in the area of 100 eV or higher, and derivations of the flow parameters are uncertain. The ion temperature and the flow speed become lower by about 50 eV after crossing the magnetic pile-up boundary. It is concluded that the observed velocity and temperature profiles can be explained on the basis of charge exchange processes.

Kettmann, G.↗