The orbit of Ariel 4 (1971 - 109A)

The definitive orbit of Ariel 4 was computed, from Minitrack observations, for the two periods during which orbital parameters were required for use in telemetry analysis - from December 1971 (launch) to May 1973, and from October to December 1973. The orbit was represented by a model with eight independent orbital parameters, and the values of these parameters were determined, and are listed, at three-day intervals. The accuracy was much the same for all the determinations, being about 0.000004 in eccentricity and 2 in. for the angular parameters; this would correspond to a nominal position accuracy of about 120 m in using the orbital parameters, though the actual errors may have approached 500 m at times, arising from perturbations due to unmodelled tesseral harmonics.