Knowledge on in situ spectral characteristics of individual end-members are essential as they provide much needed base for analysing the data obtained through remote sensing systems. This study intends to develop a comprehensive spectral library for different coral reef species and its associated benthic compositions present in Gulf of Mannar, India. In this regard, a field programme was designed to acquire different radiometric quantities that belong to different coral reef benthic compositions. Radiometric quantities for each end-member is recorded based on two different conditions (i) in situ and (ii) exposed. These two modes of measurements helped in understanding the confounding effect of water column in spectral characteristics of coral reef environments. Once the radiometric quantities were acquired from field, further steps such as deriving reflectance parameters, removal of non-illuminated wavebands, smoothing of signatures, checking for consistency, and compilation of spectral signatures to formulate a spectral library were performed. Further, compilation of spectral signatures to develop a comprehensive spectral library was carried out using spectral library building module of ENVI-5.1.

了解单个端元的原位光谱特性是必不可少的，因为它们为分析通过遥感系统获得的数据提供了急需的基础。本研究旨在为印度马纳尔湾的不同珊瑚礁物种及其相关底栖成分开发一个综合光谱库。在这方面，设计了一项实地计划，以获取属于不同珊瑚礁底栖成分的不同辐射量。根据两种不同的条件 (i)原位记录每个末端成员的辐射量(ii) 暴露。这两种测量模式有助于了解水柱对珊瑚礁环境光谱特征的混杂影响。从现场获取辐射量后，将执行进一步的步骤，例如导出反射参数、去除非照明波段、平滑特征、检查一致性以及编译光谱特征以制定光谱库。此外，使用 ENVI-5.1 的光谱库构建模块进行光谱特征的编译以开发综合光谱库。