G. V. Groves

Bio: G. V. Groves is an academic researcher from University College London. The author has contributed to research in topics: Satellite & Rocket. The author has an hindex of 4, co-authored 4 publications receiving 48 citations.

Effect of the Earth's Equatorial Bulge on the Life-time of Artificial Satellites and its use in determining Atmospheric Scale-Heights

Abstract: PREVIOUS correspondents1–3 have discussed the derivation of a simple formula for the life-time T of an Earth satellite. The formula concerned is: where P is the period, dP/dt the rate of change of period with time, e the eccentricity, a the semi-major axis and 1/k the atmospheric scale-height. This formula is valid provided e is both sufficiently small and sufficiently large, and the last two terms on the right-hand side (given here for the first time) indicate the limitations on e.

Irregularities of Satellite Drag and Diurnal Variations in Density of the Air

Abstract: A MARKED change in the slope of the period–time curves of Sputnik 2, Sputnik 3 and Sputnik 3 rocket has been reported, and from this it has been thought probable that the density of the air at a height of 220 km. increases considerably1 somewhere between lat. 35° N. and 28° N.

Air Density in the Upper Atmosphere from Satellite Orbit Observations

Abstract: FROM the rate of change of period of a satellite, it is possible to derive the density of the atmosphere at the altitude of the perigee of the orbit. Now that some ten successful satellite launchings have taken place, giving orbits with various perigee heights, the variation of air density with height can be derived over a considerable range of altitude. Many perigee heights have been less than 230 km., the exceptions being Explorer IV (1958 ζ) at 260 km; Explorer I (1958 α) at 365 km., Vanguard I (1958 β 2) at 656 km., and the recently launched Vanguard II (1959 α) at 558 km. The air density at greater heights is therefore less well established. From an analysis of data from six different satellites, the smoothed set of values in Table 1 has been derived. The accuracy, estimated by fitting a quadratic variation with height to the logarithm of the density, is of the order of 20 per cent at the lower heights and 50 per cent at the greater heights.

Some properties of upper atmosphere dynamics.

Abstract: A unifying description is provided of some important dynamic properties of the upper atmosphere in composition and temperature characteristic of a variety of phenomena, including diurnal and seasonal tides, magnetic storms, and momentum coupling with the magnetosphere. A theoretical multiconstituent model is used which can link the large-scale variations of composition and temperature to the dynamics and energetics of the thermosphere. Global mean properties of the thermosphere are reviewed, and an attempt is made to convey some understanding of the dynamic properties of energy and diffusive mass transport in the thermosphere. Attention is given to sources of energy for the thermosphere, the transport processes involved in the solar diurnal tide of the thermosphere, energy and particle sources for the annual tide, feedback from composition changes to wind-field and temperature variations, energy deposition in the thermosphere during magnetic storms and substorms, and momentum source signatures in the thermosphere.

Production and prediction of sporadic E

Abstract: This is a survey of the experimental observations and theories of formation of all types of sporadic E. The wind-shear theory is most likely to explain temperate-zone sporadic E. In the equatorial zone, VHF reflections are most probably due to the two-stream plasma instability, though gradient instabilities may play a part in producing the irregularities that cause HF vertical-incidence reflection. In the auroral zone, energetic particles dumped by any one of a variety of mechanisms cause ionization. This ionization has to be moved into thin layers of irregularities to cause auroral sporadic E and radio aurora reflections. Many recommendations are made to further the understanding of and the prediction of sporadic E for communication purposes.

A variable atmospheric-density model from satellite accelerations

Abstract: The analysis of satellite accelerations leads to an empirical formula that relates the product ρH½ (ρ = atmospheric density, H = scale height) to the geometric height z, the 20-cm solar flux F20, and the angular distance ψ′ from the center of the diurnal bulge. Once the numerical parameters of this formula have been established, tables of ρ and H are computed and a separate formula is derived to represent ρ in function of the same variables.

Determination of the Structure of the Atmosphere between 90 and 250 km by means of Contaminant Releases at Woomera, May 1968

Abstract: Two Skylark rockets were launched from Woomera rocket range, Australia (31 degrees S) on the morning and evening of 31 May 1968. Coordinated series of measurements of neutral atmospheric wind velocity, turbulent structure, temperature and density were made during each launch between 90 and 250 km altitude, combining the experimental techniques of the two groups involved. This paper attempts to construct from the combined measurements made on these occasions a dynamic picture of the interactions of atmospheric structure, and to relate the observations to previous results obtained by ourselves and other workers.