Partial Least Squares Modeling of Lunar Surface FeO Content with Clementine Ultraviolet-Visible Images - Planetary Exploration and Science: Recent Results and Advances - page 10

1.4.3 PLS Modeling of Highland Areas

As discussed above, although the two iron maps behave similarly in iron abundance
and maturity suppressing, they still exhibit discrepancy in FeO modeling of highland
regions. The iron abundance of our model for highland region is a little higher
than Lucey's, which is shown both in iron map (Fig. 1.4b, c ) and the statistical
results of iron map (Fig. 1.5 ). As is known to all, statistical methods strongly
depend on the sampling data points, i.e., when the sampling data points lack of
a specific range of FeO abundance, the result may tend to behave deviate from
that range. During the modeling, although six supplementary data are added for
lunar sampling stations, the highland data sources are only composed of Apollo 16
sampling stations and 3 added lunar farside sites. The limited proportion of highland
spectra to the total modeling data may lead to the overestimation of iron abundance
in highland areas during the PLS modeling. To testify this hypothesis, we derive
another iron model using only Apollo 16 and Apollo 17 sampling sites, in order to
increase the proportion of highland sampling sites. Data processing pipeline follows
the first PLS model (Eq. 1.5 ).
Applying this highland model to test area, we derive a new iron map. Iron
abundance derived by highland model (Fig. 1.6c ) is obviously less than that

PLS model of
highland area Lucey 2000 PLS model

FeO wt.%
19.0

9.5

0

Fig. 1.6 Iron map comparison, highland regions are indicated by a black frame. ( a ) Lucey's result;
( b ) the first PLS model result; ( c ) highland modeling result. The iron abundance of c in the highland
regions is obviously less than b and a