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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Consistency of laboratory measurements of ion-molecule reaction rates and recombination coefficients with mass spectrometric data on ionospheric ion density
Ionospheric reaction rates for oxygen nitrogen ion-atom interchange
Ion-molecule reaction rates and recombination coefficients from mass spectrometric ionospheric data
The accuracy of single-frequency ocean altimeters benefits from calibration of the total electron content (TEC) of the ionosphere below the satellite.
The Federal Aviation Administration's wide-area augmentation system (WAAS) for GPS positioning requires near real-time calibration of ionospheric vertical delays at a set of Earth-fixed grid points.
Seasonal and annual longitudinal variations in ionospheric ion distribution, stressing solar geomagnetic control importance
The frequency of occurrence and characteristics of upflowing ions (UFI) in the polar cap and auroral ionosphere are examined statistically using data from the Atmospheric Dynamics Explorer I. A total of 43,000 measurements of the UFI were made from 1981-83, and covered both masses and energies of the ions. The data indicated that many UFI observed at high altitudes originated as low altitude conical or perpendicular ions. The peak source of the ions was below 23,000 km and was latitude and time dependent. The frequency of O+ conics decreased with altitude relative to the H+ conics. The O+ and H+ conics distributions both, however, displayed dawn-dusk asymmetries that favored the dusk sector.
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In this paper, the sounder instrument and its design constraints and parameters are described.
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Amplitude scintillations of radio beacons aboard the ATS-6 satellite on 40 MHz, 140 MHz and 360 MHz recorded during the ATS-6 phase II at an equatorial station Ootacamund (dip 4 deg N) and the ionograms at a nearby station Kodaikanal (dip 3.5 deg N) are examined for scintillation activity. Only sporadic E events, other than Es-q, Es-c or normal E are found to be associated with intense daytime scintillations. Scintillations are also observed during night Es conditions. The amplitude spread is associated with strong scintillations on all frequencies while frequency spread causes weaker scintillations and that mainly at 40 MHz.
A list of ISIS 2 experiments and a description of the satellite are presented. Instrumentation of the satellite included an auroral scanning photometer, a red line photometer, a swept frequency sounder, an ion mass spectrometer, and triaxial fluxgate magnetometer. Data format descriptions are provided. Included with the geophysical data set is a list of all passes.
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This paper examines the impact that solar cycle 24 storms are likely to have on both the threat model and on the consequent availability of the system, and it proposes a means of improving WAAS availability without sacrificing system integrity.