A revised algorithm for calculating TiO2 from Clementine UVVIS data: A synthesis of rock, soil, and remotely sensed TiO2 concentrations
Article first published online: 25 FEB 2003
Copyright 2003 by the American Geophysical Union.
Journal of Geophysical Research: Planets (1991–2012)
Volume 108, Issue E2, February 2003
How to Cite
2003), A revised algorithm for calculating TiO2 from Clementine UVVIS data: A synthesis of rock, soil, and remotely sensed TiO2 concentrations, J. Geophys. Res., 108, 5009, doi:10.1029/2001JE001515, E2., , and (
- Issue published online: 25 FEB 2003
- Article first published online: 25 FEB 2003
- Manuscript Accepted: 1 AUG 2002
- Manuscript Revised: 9 JUL 2002
- Manuscript Received: 14 MAY 2002
- mare basalt;
- remote sensing;
- basalt chemistry;
 Investigating mare basalt compositions, at both the sample and remote-sensing level for the Apollo and Luna mare sites, reveals the need for a more complex regression procedure than previously proposed in order to extract accurate TiO2 concentrations from Clementine spectral reflectance (CSR) data. The TiO2 algorithm of Lucey and coworkers is modified by using two different sets of regression parameters to relate measured regolith compositions from sampling locations to the CSR properties of these sites. One regression trend fits the majority of Apollo data, and the second regression is a fit to the Apollo 11, Luna 16, and Luna 24 data, which were considered to be anomalous in previous TiO2 calibrations. These three sites have unusually low albedo compared to other mare landing sites, and some 32% of nearside mare regions appear to share this characteristic. Possible reasons for these differences related to proximity of the other sites to mare-highland boundaries are discussed. Using the dual-regression method, we find (1) that TiO2 concentrations calculated for the basaltic landing sites faithfully reproduce a bimodal distribution as seen in the sample data, (2) that when coupled with the effects of other thermal neutron absorbers, Ti concentrations are more consistent with observed epithermal-to-thermal neutron-flux ratios than are previous Clementine-based derivations of TiO2 for basaltic regions, and (3) that basalts of intermediate-TiO2 concentrations occur most frequently in the Oceanus Procellarum region and that these intermediate concentrations appear to be inherent to the flows underlying the regolith and presumably to the basalt source regions.