SeaWinds on QuikSCAT is the latest of NASA's wind-observing scatterometer missions. It was launched in June of 1999 with the goal of accurately measuring wind fields over all the oceans. It has also proven to be valuable in monitoring ice changes in polar regions. The value of such data necessitates an extremely accurate and precise calibration of both satellite performance and instrument measurements. In order to assure optimal performance a Calibration Ground Station has been constructed, which provides direct measurements of the instrument transmissions. Each time the spacecraft flies overhead, approximately twice a day, the CGS passively captures microwave pulses transmitted from QuikSCAT. The data is then used with various processing and analysis techniques to validate the system performance and calibration. As part of the calibration analysis, a software simulation model of the instrument system has been constructed. This model is able to simulate critical instrument systems and path loss characteristics and thus predict CGS receive data for any given satellite pass. By comparing model-based simulation data with actual recorded CGS data, calibration of parameters such as system timing, power, attitude, and Doppler compensation can be accurately determined. The analysis has been able to validate the Doppler/range compensation algorithm, instrument timing, and other key system operational parameters. The major contributions of the CGS-based analysis are demonstration of pointing accuracy and overall system stability of SeaWinds. By employing a variance minimization technique between simulated and actual data, the QuikSCAT platform is shown to be extremely stable.