Iran is the second largest gypsum producer in the world. There are still potential areas for the exploration of the new gypsum deposits. Regional scale investigation is an important preliminary step in mineral exploration. Advanced spaceborne thermal emission and reflection radiometer (ASTER) images were used for mapping of the gypsum deposits in Roydar basin, in southern Iran. The objective of this study is to identify gypsum-bearing areas with economic value using ASTER data. The present research utilized various image-processing techniques, including false color composite (FCC), band ratios (BR), and spectral angle mapper (SAM). Four reference spectra used in SAM method. Two reference spectra were selected from the USGS and IGCP libraries, respectively. Two other spectra extracted from ASTER images, corresponding to the known sampled locations. This study showed that FCC images of ASTER bands are quick, easy, and efficient method to identify gypsum-bearing areas. We proposed six different groups of the FCCs to separate gypsum layers. The use of extracted spectra from ASTER image, as the reference spectra, is better than IGCP and USGS spectra from the spectral libraries in identifying gypsum-bearing areas by SAM method. The [(B3 × B8)/(B5 × B6)]–(3/2) band ratio demonstrated that gypsum-bearing rocks are enhanced better than the FCC & SAM techniques. The results were evaluated for accuracy assessment by field checking and sampling.

伊朗是世界第二大石膏生产国。新石膏矿床仍有勘探潜力。区域尺度调查是矿产勘查的重要前期步骤。先进的星载热发射和反射辐射计 (ASTER) 图像被用于绘制伊朗南部 Roydar 盆地的石膏矿床。本研究的目的是使用 ASTER 数据确定具有经济价值的含石膏区域。目前的研究利用了各种图像处理技术，包括假彩色合成 (FCC)、带比 (BR) 和光谱角映射器 (SAM)。SAM 方法中使用的四个参考光谱。两个参考光谱分别选自 USGS 和 IGCP 库。从 ASTER 图像中提取的另外两个光谱，对应于已知的采样位置。这项研究表明，ASTER 波段的 FCC 图像是识别含石膏区域的快速、简单和有效的方法。我们提出了六组不同的 FCC 来分离石膏层。使用从 ASTER 图像中提取的光谱作为参考光谱，在通过 SAM 方法识别含石膏区域方面优于光谱库中的 IGCP 和 USGS 光谱。[(B3 × B8)/(B5 × B6)]-(3/2) 波段比表明含石膏岩石的增强效果优于 FCC 和 SAM 技术。通过现场检查和抽样评估结果的准确性评估。作为参考光谱，SAM 方法在识别含石膏区域方面优于光谱库中的 IGCP 和 USGS 光谱。[(B3 × B8)/(B5 × B6)]-(3/2) 波段比表明含石膏岩石的增强效果优于 FCC 和 SAM 技术。通过现场检查和抽样评估结果的准确性评估。作为参考光谱，SAM 方法在识别含石膏区域方面优于光谱库中的 IGCP 和 USGS 光谱。[(B3 × B8)/(B5 × B6)]-(3/2) 波段比表明含石膏岩石的增强效果优于 FCC 和 SAM 技术。通过现场检查和抽样评估结果的准确性评估。