Hard X-ray latitude effect measured during a transatlantic balloon flight

The hard X-ray latitude effect, as measured by two X-ray scintillator detectors, is reported in the range of McIlwain shell parameter L from 1.4 to 2.6 (earth radius units). The data analysis method used to measure the flux from weak X-ray sources is also given.     

Performance of an Electrically Small Antenna Amplifier Circuit

A technique is presented to calculate the noise figure and available power gain for electricially small antenna amplifier circuits over a wide bandwidth. The method permits reasonable predictions of circuit performance solely from the manufacturer's transistor data, i.e., without resorting to extensive measurements. Results for a system designed for 10 kHz to 500 MHz coverage are presented. The agreement between the calculated and measured noise figures and available power gain is within 3 dB over most of the frequency range.     

Magnetic launching in outer space

We examine the idea of accelerating a space ship, carrying a magnetic dipole moment, in a long inhomogeneous magnetic field. It is shown that it is technically possible to impart a mass of 10 tons a speed greater than the escape velocity of the solar system. We consider the flow of energy and give a rough calculation of the main parameters of the launching device. The device can be used continually and can decelerate a spacecraft with dipole moment equally well.     

On state estimation for an orbiting single tether system

The effects of instrumentation accuracy and configuration on estimation error are studied for the small expandable-tether deployment system (SEDS) using a continuous-discrete extended Kalman filter (CDEKF) state estimator. A twelfth order model that incorporates the rigid body modes of the tether as well as the satellite attitude dynamics is developed. Simulation results using the model and the estimator indicate that the originally planned instrumentation package could not estimate the state vector adequately. Recommendations are made and results presented that reduce the estimation error by adding instruments and increasing selected measurement accuracies     

Oxygen and Iron Ions at High Heliolatitudes

The fluxes of O and Fe ions at high heliolatitudes measured by the HiScale instrument on Ulysses reflect the dynamical processes that affect the charged particle populations in the heliosphere. Both the O and Fe ions show more latitude dependence in the first (solar minimum) orbit to high southern heliolatitudes than during the second (solar maximum) orbit. The ion fluxes are larger during the solar minimum orbit; the flux levels are influenced by the occurrence of corotating interaction regions. The Fe/O abundance ratios are found to be similar at 1 AU and at high heliolatitudes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Development of a Low-Power Digital Inertial Reference Assembly

Current and projected system requirements for inertial reference assemblies emphasize high accuracy, long life, and low power. An inertial reference assembly ( IRA) which embodies the aforementioned characteristics was developed recently. Pulse rebalanced gas-bearing gyroscopes were used to attain high accuracy and long life. Temperature compensation of gyroscope parameters (in lieu of temperature control) and dual voltage spinmotor operation helped achieve low-power operation. The latter two items represent an advancement in the state of the art and form the subject of this paper. These techniques were used in the construction of a three-axis IRA with an operating power less than 50 watts. It has achieved 0.1 percent scale factor accuracy over a 60°F range.     

Representations of solar EUV fluxes for aeronomical applications

The development of significantly improved representations of solar EUV inputs for computer-aided investigations of the terrestrial thermosphere and ionosphere has become attractive particularly for the present solar cycle which has been covered by reasonably complete and continuous EUV observations from the AE-E Satellite. These representations try to satisfy some rather incongruous $\text{requirements of spectral detail}$, regarding (a) the strong wavelength-dependence in the $\text{terrestrial}$ atmospheric cross sections of the various types of EUV photon interactions, (b) the great differences in the relative amplitudes of the various types of variations in the full-disk fluxes of $\text{solar}$ emissions at different wavelengths, and (c) the persisting desire to use only a $\text{small number of daily indices}$ as actual input variables for computational models supposed to cover the entire EUV wavelength range (remembering the great success of empirical thermospheric models using only two indices). These general physical and specific aeronomical demands indeed outline a very difficult task. The present study, based mainly on AE-E satellite observations during 1976–1979, represents an exploratory step, only clarifying some important developmental aspects, without recommending any specific formulations for immediately practicable adoption in aeronomical modelling at this time.     

Quasistationary outflow of gases from solar active regions

The author's finding that active regions are sources of relatively slow and approximately radial quasistationary corpuscular streams is confirmed by using the fact that active regions are closely connected with coronal holes. Furthermore, attention is paid to numerous papers according to which the active regions characterized by enhanced and prolonged chromospheric (flare) activity are also sources of quasistationary corpuscular streams. Velocities of gases in these streams are higher than velocities of gases in streams from “quiet” active regions.On the basis of all these studies it is suggested that the origin of outflow of plasma from “quiet” active regions and from active regions with enhanced flare activity is the same and is due to some continuous non-stationary processes in the active regions. The velocity of gases in all these streams grows with increasing continuous flare activity in the active regions.It is concluded that quasistationary corpuscular streams from active regions with enhanced flare activity are important sources of cosmic rays from the sun.