Estimates of the Lunar Surface Composition with Clementine Images and Lscc

Introduction: There have been several approaches to develop remote sensing technique to estimate composition of the lunar surface using multispectral observations. We present a new approach based on statistical analysis of spectral and compositional data for lunar samples by the Lunar Soil Characterization Consortium (LSCC) and using the UVVIS Clementine data with 1 km resolution. This technique allows us to estimate and map the abundance of TiO2, SiO2, and FeO, pyroxene and plagioclase content, and maturity degree (Is/FeO). Data and Their Analysis: We use data for LSCC -characterized mare soils of the Apollo-11, 12, 15, and 17 missions [1] and recent data for several Apollo-14 and -16 soils (highland regolith). Coordinated compositional and spectral measurements were carried out for samples with controlled particle size: <10 μm, 10-20 μm, and 20-45 μm. We used 42 samples for analysis. Bi-directional spectra were obtained with the RELAB spectrometer in the spectral range 300–2600 nm [2]. We have transposed the soil spectra to the Clementine spectral bands (415, 750, 900, 950, and 1000 nm). The main point of our approach is to find relationships that provide the highest correlation coefficients between different linear combinations of optical parameters, on one hand, and chemical/mineral composition and degree of maturity, on the other hand. We used the following optical parameters: albedo AR = A(750 nm), color-indexes: CBR = A(415 nm) / A(750 nm), CIR1 = A(900 nm) / A(750 nm), CIR2 = A(950 nm) / A(750 nm), CIR3 = A(1000 nm) / A(750 nm), and bend D = A(750 nm) A(1000 nm) / [A(900 nm)]. An optimal empirical expression to derive high correlation coefficients is: logP = aAR(%)+bCBR+cCIR1+hCIR2+ eCIR3+fD+g, where P is a studied parameter. The weight coefficients a, b, c, h, e, f, and g minimize the RMS deviations of the calculated values of P from the measured values. Using the current set of LSCC data these coefficients are given in the following Table: a b c h e f g TiO2 -0.040 1.873 50.662 -17.747 -13.531 13.011 -32.542 FeO -0.023 0.349 24.664 -15.632 -1.233 5.190 -11.968 SiO2 0.002 -0.214 -2.091 -0.554 1.597 -0.736 3.511 Py -0.023 0.079 16.771 -19.487 4.959 1.666 -2.782 Pl 0.016 0.861 -6.888 7.360 -1.527 -0.322 1.972 Is/FeO -0.013 -2.466 -35.496 17.736 5.303 -10.710 26.712