## 2 Data and Preprocessing  
### LSCC Data  
The research material is the results of measurements in the Earth's laboratory on samples transported from the moon, and the reflectance measurements are taken at Brown University, and the dataset is publicly available, and can be freely accessed \"[[https://www.planetary.brown.edu/relab](https://www.planetary.brown.edu/relab)]([https://www.planetary.brown.edu/relab](https://www.planetary.brown.edu/relab)) (accessed on 10 January 2022)\". LSCC (Lunar Soil Characterization Consortium) lunar soil sample data consists of 10 lunar highland lunar soil samples collected by Apollo 14/16 and 9 lunar soil samples collected by Apollo 11/12/15/17. These data are widely used in the field of lunar research, including lunar soil spectrum, mineral composition and content, particle size, maturity and other information, which have a high degree of recognition and authority ([[http://apps.geology.brown.edu/RELAB.php](http://apps.geology.brown.edu/RELAB.php)]([http://apps.geology.brown.edu/RELAB.php](http://apps.geology.brown.edu/RELAB.php)) accessed on 10 January 2022). All the spectral data of LSCC are measured in Brown University's RELAB laboratory under the conditions of an incident angle of 30 degrees and an exit angle of 0 degrees. LSCC is the only complete \"ground reality\" data on the moon, including the reflectance spectra and mineral abundance information of lunar regolith [5]. LSCC consists of 10 samples of lunar highland collected by Apollo 14/16 and 9 samples of lunar mare collected by Apollo 11/12/15/17 [10, 11, 12]. All the 19 original samples have been subdivided into four groups of <10 \(\upmu\)m, 10-20 \(\upmu\)m, 20-45 \(\upmu\)m and <45 \(\upmu\)m according to the particle size, a total of 76 samples. The reflectance spectra of all samples and the mineral content of the first three particle size groups have been measured by RELAB Laboratory of Brown University. All spectra were obtained at i (incident angle) = 30 degrees, e (emergence angle) = 0 degrees, and g (phase angle) = 30 degrees. The spectral resolution is 5 nm, forming a spectral database of 460 bands from 300 to 2600 nm [9,10]. Three particle size groups < 10 \(\upmu\)m, 10-20 \(\upmu\)m and 20-45 \(\upmu\)m were selected in this paper which have both spectral data and mineral abundance information. The particle size group of <45 \(\upmu\)m lacks mineral content information and is not considered as the research object. Plagioclase is widely distributed in the lunar sea and lunar highlands. Plagioclase in the lunar soil is poor in sodium and rich in calcium, and has relatively strong absorption near 0.65 \(\upmu\)m and 1.25 \(\upmu\)m, but it is not easy to observe in the lunar soil. This is because the absorption characteristics of plagioclase are weaker than other strong absorption minerals and can easily be concealed. By decomposing and filtering data information, PLS extracts the most explanatory comprehensive variables for dependent variables, identifies the information and noise in the system, and better overcomes the adverse effects of multiple correlations of variables in system modeling. The mineral contents of lunar mare and lunar highland are different. Lunar highland contains more plagioclase, so the spectra of lunar mare (Figure 1a) and the spectra of lunar highland are quite different (Figure 1b). Besides, plagioclase is widely distributed in the lunar sea and lunar highlands. Plagioclase in the lunar soil is poor in sodium and rich in calcium, and has relatively strong absorption near 0.65 \(\upmu\)m and 1.25 \(\upmu\)m, but it is not easy to observe in the lunar soil. This is because the absorption characteristics of plagioclase are weaker than other strong absorption minerals and can easily be concealed. By decomposing and filtering data information, PLS extracts the most explanatory comprehensive variables for dependent variables, identifies the information and noise in the system, and better overcomes the adverse effects of multiple correlations of variables in system modeling.