Engineering topics

Andre, C. G.

Publications and source records attributed to Andre, C. G..

20 records · Page 2

NASA NTRS1974

The application of trend surface analysis to a portion of the Apollo 15 X-ray fluorescence data

X-ray fluorescence data for 8 and 16 second time integrals gathered by Apollo 15 in circum lunar orbit were analyzed to determine the capability for chemical mapping of relatively small lunar features in a portion of Tranquillitatis and Serenitatis basins. Spatial mapping using trend surface analysis demonstrated that a useable signal could be extracted from Al/Si intensity ratios calculated for 8 second time spans. Reliability of the Al/Si ratio was enhanced when 16 second data were compiled using a sliding average technique. Residual anomalies from the trend surface mapping were identified and correlated with relatively small lunar surface features.

Podwysocki, M. H.↗

NASA NTRS1974

The application of trend surface analysis to a portion of the Apollo 15 X-ray fluorescence data

The present work discusses some useful techniques for the detailed chemical mapping of the lunar surface from X-ray fluorescence data, using Al/Si and Mg/Si intensity ratios and preliminary geologic interpretations of some relatively small lunar physiographic features. It is shown that these features can be distinguished as anomalies by employing trend surface analysis on the data. Some correlations between albedo differences and elemental ratios can be found within mare areas. A useful lower limit of 16 seconds is established for time integrals of Al/Si intensity ratios. It was not possible here to determine the minimum time integration necessary for the best spatial mapping of the Mg/Si data.

Podwysocki, M. H.↗