14th-order harmonics in the geopotential from analysis of satellite orbits at resonance

Analysis of 208 US Navy orbits for the satellite 1970-47B at 14th-order resonance

The orbit of 1970-47B passed very slowly through 14th-order resonance, and the changes in orbital inclination and eccentricity have been analysed over a four-year period, from January 1977 to January 1981, using 208 US Navy orbits. The analysis has yielded values for three pairs of lumped harmonic coefficients of 14th order, which have...

Individual geopotential coefficients of order 15 and 30, from resonant satellite orbits

The analysis of variations in satellite orbits when they pass through 15th-order resonance (15 revolutions per day) yields values of lumped geopotential harmonies of order 15, and sometimes of order 30. The 15th-order lumped harmonies obtained from 24 such analyses over a wide range of orbital inclinations are used here to determine individual...

Geopotential harmonics of order 15 and 30, from analysis of the orbit of satellite 1971-10B

The satellite 1971-l0B passed through exact 15th-order resonance on 1981 March 30, and orbital parameters have been determined at 52 epochs from some 3500 observations using the RAE orbit refinement program, PROP, between 1980 September and 1981 October. The variations in inclination and eccentricity during this time have been analysed, and six...

Geopotential coefficients of order 29, from analysis of the orbit of satellite 1967-104B

Upper-atmosphere zonal winds from satellite orbit analysis

We review and interpret the values of upper-atmosphere rotation rate (zonal winds) obtained by analysing satellite orbits determined from observations.

The last 14 days of Skylab 1: orbit determination and analysis

The orbit of Skylab 1 (1973-27A) has been determined using some 1400 NORAD observations during the 14 days prior to decay on 1979 July 11. There are 14 daily orbits, with standard deviations corresponding to average accuracies of 40 m cross track and 30 m radial. A 15th orbit, only slightly less accurate, was determined from observations on July...

Analysis of the orbit of 1966-63A near 15th-order resonance

Geopotential harmonics of order 29, 30 and 31 from analysis of resonant orbits

Evaluation of 15th-order harmonics in the geopotential from analysis of resonant orbits

Satellite orbits contracting under the influence of air drag experience 15th-order resonance when the track over the Earth repeats after 15 revolutions. If the orbital decay rate is slow enough, an orbit passing through the resonance is appreciably perturbed by the effects of 15th-order harmonies in the geopotential. We have used the observed...

Analyses of the US Navy orbits of 1963-24B and 1974-34A at 15th-order resonance

The orbits of the two satellites 1963-24B (Tiros 7 rocket, at inclination 58.20) and 1974-34A (Intercosmos 11, at inclination 50.60 ) passed slowly through 15th-order resonance within 6 months of each other in 1976-77. The changes in their orbital inclinations and eccentricities have been analysed, using 112 weekly US Navy orbits for 1963-24B...

Samos 2 (1961alpha1): orbit determination and analysis at 31:2 resonance

Samos 2, 1961alpha1, launched on 31 January 1961, was the first satellite to enter a sun-synchronous orbit at an inclination of 97.4º. The initial perigee and apogee heights were 474 km and 557 km respectively, the initial period was 94.97 minutes and the satellite decayed on 21 October 1973 after more than 12 years in orbit. Samos 2 passed...

Evaluation of 14th-order harmonics in the geopotential

Application of a photographic method to study the luminance distribution governing visibility in night driving

The effect of atmospheric winds on satellite orbits of high eccentricity

The fatigue strength of butt-welded and plain specimens of 18(250) maraging steel plate

Fatigue tests in pulsating tension on samples of 18(250) maraging steel plate, both with and without central transverse butt welds, are reported. Tests are also described in which the weld be ad was removed by grinding. The results obtained from the plain plate, which was tested as rolled and aged, were inferior to those reported by other...

Measurements of transient pressures on a narrow-delta wing due to an upward gust

With the aid of a new research facility, transient pressures have been measured on the upper surface of a narrow-delta wing when it entered a sharpedged gust normal to the wing plane. This paper describes the facility and presents an analysis of the results of six runs through the gust by ons model. It is shown that the pressure distribution on...

Techniques for the investigation of aerodynamic-heating effects in free flight

This paper describes the methods currently in use by Aerodynamics Department of the Royal Aircraft Establishment for the investigation of aerodynamic-heating phenomena using rocket-propelled free-flight test vehicles. The main concern of the paper is with the measurement of heat transfer, but there are brief comments on some simple methods of...