Analysis of the orbit of intercosmos 10 rocket (1973-82B) in its last 15 days

Intercosmos 10 rocket (1973-82B) was launched on 30 October 1973 into an orbit of eccentricity 0.08 inclined at 74° to the equator, and decayed on 8 October 1977. Orbits have been determined daily in the last 15 days of its life from NORAD and U.S. Navy observations; and an orbital accuracy of about 55 m radially and 70 m cross-track was obtained. Analysis of the decrease in perigee distance has provided two values of atmospheric density scale height at heights of 190 and 200 km. The variations in orbital inclination due to atmospheric rotation and 16thorder resonance with the geopotential have been analysed, and give a morning value for the atmospheric rotation rate of 0.90 ± 0.06 rev day ^-1 at a height of approximately 200 km and two values for lumped 16th-order harmonic coefficients with accuracies equivalent to 1.5 and 5.0 cm in geoid height.