Comparison ofTeandTifrom Ogo 6 and from various incoherent scatter radars

Abstract

Langmuir probe and retarding potential analyzer (RPA) data on the electron and ion temperatures Te and Ti obtained from Ogo 6 are compared with Te and Ti values obtained from the incoherent scatter network. The satellite to radar temperature ratio TeS/TeR is 1.15 on the average for these comparisons. This discrepancy is larger than the uncertainties usually placed on the probe and radar Te values. It is, however, a smaller discrepancy than that found in many previous comparisons of this type. Our data do not appear to give any insight into the cause of the discrepancy. The ion temperature ratio TiS/TiR is approximately 1.0, independent of the particular radar examined. The internal accuracy of the RPA Ti data set was ±5% or better. Thus this comparison serves as an intercalibration of the incoherent scatter network. Since no significant systematic errors (i.e., errors larger than the statistical errors) exist between the RPA and radar Ti data, it appears very unlikely that any significant systematic errors exist in either data set. It should be noted, however, that the comparison data were limited to mainly nighttime hours and thus to relatively low temperatures and were heavily weighted to altitudes between 400 and 600 km, where suspected sources of systematic error are minimum.