Typical CHAMP Density and Wind Errors:
This page presents a summary or errors associated with density and wind calculations; however, the errors found in the corresponding data files will be reduced because multiple data points are averaged within pre-determined latitude bins. The histograms below represent errors in the density and wind measurements for the period of 2001-2007. The sources of error have been separated into the two categories of systematic and noise errors. The main constituents of systematic error are the estimated bias and scale factors that are applied to the along-track and cross-track accelerometers, and the (likely underestimated) coefficients of drag and lift. Noise error is caused mostly by the precision of the accelerometer, winds that are assumed to be zero in density and cross-track wind speed calculations, and inaccuracies in the solar radiation pressure (SRP) model.
Combining the systematic and noise errors yields the total error, shown in the figure above [Sutton, 2008], for density.
The figure above [Sutton, 2008] combines the systematic and noise error to show the total error in wind measurements.
References:
Sutton E.K. (2008), Effects of Solar Disturbances on the Thermosphere Densities and Winds from CHAMP and GRACE Accelerometer Data, PhD Dissertation, University of Colorado at Boulder.