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Additional Results
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Verified an instrument antenna rotation rate of 18.0109 rpm versus the nominal 18 rpm. By analyzing the reported instrument antenna angle, and comparing modeled pulses with those received at the ground it was determined that the precise antenna rotation rate was 18.0109 rpm versus the nominal rate of 18 rpm.
Identified antenna rotation wow and low speed variation. The instrument antenna does not rotate at a constant 18.0109 rpm. It tends to speed up and slow down over a long period of time, which is called wow. This low speed variation can be observed by the spacing of pulses at the CGS.
Verified onboard implementation of the range/Doppler tracking tables. The Seawinds instrument precalculates the Doppler shift of a pulse and compensates for it so that when the pulse returns it will have a nominally constant frequency. The Doppler calculations are made using onboard range / Doppler tracking tables. By comparing the Doppler shift of the pulses received at the CGS to the model generated pulses which use the tables, it was shown that the Doppler calculation tables are operating correctly.
Verified spacecraft attitude to within +/- 0.1 deg, with continuing further refinement. By using the minimization techniques describe earlier, the roll, pitch, and yaw of the spacecraft have been determined to within 0.1 degree for each axis. Further refinement is in process.
Confirmed transmitted power to within +/- 2.0 dB, with further refinement continuing. Also, by using minimization techniques, the transmitted power of the instrument has been confirmed to within 2.0 dB. Further refinement is also continuing.
