Orbit Determination and Analysis for Cosmos 236 at 15th-Order Resonance
Abstract
Cosmos 236 (1968-70A) was launched on 27 August 1968 into a near- circular orbit of inclination 56 deg and is expected to decay during late 1989. The orbit has been determined from observations for 77 epochs between July 1983 and October 1984 over the time interval when the orbit was expected to be significantly influenced by the effects of 15th-order resonance with the Earth's gravitational field: Exact resonance occurred on 13 March 1984. The observations numbered over 4700, including 284 from the Hewitt cameras which are sited at Herstmonceux in England and at Siding Spring in Australia. The orbital accuracy achieved was fairly consistent throughout, with the standard deviation in orbital inclination and eccentricity corresponding on average to positional accuracies of 85 m and 65 m respectively. Analysis of the changes in inclination and in eccentricity at resonance has given values of three pairs of lumped harmonics of order 15 and three pairs of eccentricity. The values from inclination had standard deviations equivalent to accuracies in geoid height of 0.6 cm and 2.0 cm for orders 15 and 30 respectively while the equivalent accuracies for the values from eccentricity were 1.6 cm and 6.0 cm. Keywords: Orbital determination; Orbit analysis; Geopotential harmonics; Satellite orbits: Resonance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA205316
Entities
People
- A. N. Winterbottom
Organizations
- Royal Aircraft Establishment