Identifying physical properties of geothermal features such as surface temperature and roughness is crucial for geothermal assessment, hydrology, and environmental studies. Surface temperature and roughness-related rock properties strongly influence the thermal infrared and back-scattering intensities, respectively, of synthetic aperture radar (SAR) images. This study aimed to identify geothermal steam spots based on the surface temperature and roughness of altered surfaces, mud pools, and hot springs in tropical conditions. The thermal emissivity separation method was adopted to calculate kinetic temperature using the thermal infrared (TIR) of the advanced spaceborne thermal emission and reflection radiometer (ASTER) data as well as ground temperature data. Surface temperatures calculated by the thermal emissivity separation method were corrected using measured ground temperatures to eliminate the effects of atmospheric absorption, thermal inertia of materials, and/or diurnal temperature in the images. In addition, the linear fitting method was applied to obtain the final surface roughness model based on the calculated determination coefficient (R²) between the initial surface roughness model derived by Sentinel-1A SAR and field data. The highest R² between surface roughness values from Sentinel-1A SAR and field data were selected to calculate spatially the surface roughness of the Wayang Windu Geothermal Field, West Java, Indonesia. The satellite imagery and field measurements showed that surface temperature and roughness features correlate with each other, and high and low thermal features correlate with high and low surface roughness values, respectively. Accordingly, we integrated the TIR and SAR data to propose the thermal resistivity index (TRI) as an indicator of the hydrothermal fluid paths to the surface. Low TRI was encountered at geothermal features and intersections of subsurface faults, which indicated weak zones that radiate heat from the subsurface to the surface.

识别地热特征的物理属性（例如表面温度和粗糙度）对于地热评估，水文学和环境研究至关重要。与表面温度和粗糙度相关的岩石属性分别强烈影响合成孔径雷达（SAR）图像的热红外强度和反向散射强度。这项研究旨在根据地表温度和热带条件下地表变化，泥浆池和温泉的粗糙度确定地热蒸汽斑。采用热发射率分离方法，利用先进的星载热发射和反射辐射计（ASTER）数据的热红外（TIR）以及地面温度数据来计算动力学温度。使用测得的地面温度校正通过热发射率分离法计算的表面温度，以消除大气吸收，材料的热惯性和/或图像中的昼夜温度的影响。另外，基于计算出的确定系数，采用线性拟合方法获得最终的表面粗糙度模型（Sentinel-1A SAR得出的初始表面粗糙度模型与现场数据之间的R ²）。最高R ²选择Sentinel-1A SAR的表面粗糙度值与现场数据之间的差值，以空间计算印度尼西亚西爪哇省Wayang Windu地热田的表面粗糙度。卫星图像和野外测量表明，表面温度和粗糙度特征彼此相关，而高和低热特征分别与高和低表面粗糙度值相关。因此，我们综合了TIR和SAR数据，提出了热阻指数（TRI），作为热液流向地面的指示。在地热特征和地下断层的相交处遇到了较低的TRI，这表明薄弱的区域将热量从地下散发到地表。