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由地表风化产生的表面覆被层的矿物质，其质地或与它的基岩矿物相似，或十分不同，虽然这类表面层的厚度仅有几微米到几毫米，但它们却完全控制了地面的反射光谱。与此相似，有些由风吹送的尘埃、胶结物或其它附着物在表面形成的外层也是影响遥感反射光谱的重要因素。这种由胶结物形成的表层往往是深色（甚至黑色）的，因为它们通常出现在干旱区，故常称为“荒漠漆”（“ｄｅｓｅｒｔｖａｒｎｉｓｈ”）。尽管这些暗色对我们的眼睛并无特别之处，但这类表面层（通常为粘土）在短波红外区（ＳＷＩＲ）具有低反射率的吸收特征，并能据此推断它们的矿物成分。因此，为了要在遥感图象和地面的实际“地质状况”之间建立联系，必须对裸露岩石表面特征具有良好的了解。由于不可能在野外总能找到“新鲜”的岩石表面，因此，人们必需能将“岩石内部”物质的光谱和它“上、下表面”的光谱区分开。本部分以美国加里福尼亚东部Ｗｈｉｔｅ－Ｉｎｙｏ山区高海拔地区早古生代白云质碳酸盐的风化表面为例，研究其岩石表面风化特征与海拔高度的关系。
Surface coverings produced by surface weathering are similar or very different in texture to their bedrock minerals and although such surface layers are only a few microns to a few millimeters thick, they have complete control of the ground Reflection spectrum. Similarly, some of the outer layers of dust, cement or other attachments that are blown by the wind on the surface are also important factors that affect the remote sensing reflectance spectrum. This surface layer, which is made of cement, tends to be dark (or even black) because they are commonly found in arid regions and are often referred to as “desertvarnish.” Although these dark colors are not unique to our eyes, such surface layers (usually clays) have low reflectance absorption characteristics in the SWIR and can infer their mineral composition accordingly. Therefore, in order to establish a link between the remote sensing image and the actual “geological conditions” of the ground, a good understanding of the surface characteristics of exposed rock must be made. Since it is not always possible to find “fresh” rock surfaces in the field, one must be able to distinguish the spectrum of the “rocky interior” material from the spectrum of its “upper and lower surfaces”. In this section, the weathering characteristics of early Paleozoic dolomitic carbonates in the high-altitude area of White-Inyo, eastern California, USA, are studied to study the relationship between the weathering characteristics of rock surface and the altitude.