We present a spectral model for optical non-invasive estimation of layer thickness and water/ice content on diffusely reflecting substrate materials based on a single near-infrared spectrum. Using the wavelength range from 850 nm to 1650 nm which is readily accessible with InGaAs detectors, a wide range of layer thicknesses from tens of micrometers to several centimeters can be determined. The model is fitted without dependence on absolute signal values and requires no additional surface model given an approximately linear spectrum of the diffuse substrate material. Validation measurements from 50 µm up to 22 mm of water and ice—including the freezing process—demonstrate an excellent agreement between ground truth values and the fitted parameters of our model.

我们提出了一个光谱模型，用于基于单个近红外光谱的非侵入性光学估计层厚度和水/冰含量的漫反射基板材料。使用InGaAs探测器可以轻松到达的850 nm至1650 nm的波长范围，可以确定数十微米至几厘米的较宽的层厚度。在不依赖于绝对信号值的情况下拟合该模型，并且在扩散基板材料具有近似线性光谱的情况下，不需要其他表面模型。从50 µm到22 mm的水和冰的验证测量（包括冻结过程）证明了地面真实值与模型拟合参数之间的出色一致性。