Global and regional studies of the data abstracted from the POGO satellites have demonstrated the utility of satellite magnetometer measurements in geological studies. However, detailed examination of these data reveals that there exists a considerable amount of noise resulting from external fields and data reduction techniques. Such noise inhibits more detailed studies with the POGO data and could similarly affect the utility of data from the Magsat mission. Correlation of POGO satellite data with ground observatory records and geomagnetic indices was employed to identify the existence of external field affects and document the data reduction problems. Significant effects of the Sq current system, including the equatorial electrojet, are shown to be still in the data despite the local time screening. Such effects are totally in agreement with theoretical models of this current system and should be considered in Magsat data reduction, as the theoretical model predicts that the Sq current may at times have significant effects even at the dawn/dust local times of the Magsat orbit. The state of inflation and deflation of the magnetosphere is vividly portrayed in the POGO measurements and is well correlated with the Dst index. The ring current correction applied to the POGO data was seen to be of varying quality depending upon the state of the magnetosphere and the length of satellite tract data reduced. These effects combined with the irregular distribution of data from the individual POGO satellites can result in pseudo anomalies as evidences by a comparison of satellite data reduced in a fashion to minimize them with those previously published over the same area.