ANALYSIS OF THE ORBITAL ELEMENTS OF THE SATELLITE COSMOS 1603 (1984-106A) AT 14TH-ORDER RESONANCE

The orbital parameters of Cosmos 1603 (1984-106A) have been determined at 43 epochs from over 2900 observations, of which over 80% were supplied by the U.S. Naval Research Laboratory. Hewitt camera observations were available for 25 of the determinations. Orbital elements were determined between January and December 1987, during which time the satellite was close to 14:1 resonance. The satellite experienced the interesting property of being temporarily trapped with respect to a secondary resonance parameter due to the low air-drag in 1987. This effect gave rise to a quasi-secular increase in the eccentricity and libration of the secondary resonance variable. Analysis of the inclination and eccentricity yielded six lumped harmonic coefficients of order 14. Analysis of the mean motion yielded additional pairs of lumped harmonics of orders 14, 28 and 42, the 14th-order harmonics superseding those obtained from analysis of the inclination. The derived values were used to test the Goddard Earth Models, GEM-T1 and GEM-T2, at high order. © 1990.