Advanced Lithological Mapping Using ASTER Multispectral Imagery in Google Earth Engine

In this tutorial, we demonstrate how to perform advanced lithological mapping using ASTER multispectral imagery in Google Earth Engine. We begin by defining the study area with a polygon and centering the map over the region of interest. Next, we load the ASTER L1T image collection, filter it by the study area, select low-cloud-cover images during the summer months, and create a composite image. To improve image quality, we apply Dark Object Subtraction (DOS) atmospheric correction, enhancing visibility in the VNIR and SWIR bands while preserving the thermal bands. We then define a function to compute various lithological indices, including Kaolinite, Alunite, Calcite, Quartz, Carbonate, Mafic, Hematite, Iron Oxide, Clay, and Montmorillonite indices, based on specific band math expressions. Each index is calculated, visualized with a custom color palette, and added to the map for easy interpretation. Finally, we demonstrate how to export selected lithological index maps, such as Hematite, Kaolinite, and Montmorillonite, as GeoTIFF files directly to Google Drive for further analysis. ----------------------------------------------------------------- Resources: Code link: https://code.earthengine.google.com/a29e5a8609b4ba3d3a8efb246d215c19 ASTER L1T Radiance https://developers.google.com/earth-engine/datasets/catalog/ASTER_AST_L1T_003#bands This hands-on tutorial provides a complete workflow for enhancing lithological feature mapping using corrected ASTER data in a cloud-based environment. ----------------------------------------------------------------- 💰🤝🏻Join Membership to get access to perks & Support us🤝🏻💰 https://www.youtube.com/channel/UCYn54mq89HgZcNk0L7eon0w/join ----------------------------------------------------------------- 👩‍💻 Join the Terra Spatial Community: Engage with fellow learners, share your experiences, and get support on our dedicated community forum. 🌐 Stay connected: 📌 Subscribe to our Channel: https://www.youtube.com/@TerraSpatial... 📌 Facebook: https://www.facebook.com/terraspatial/ 📌 Geosuite blog: https://geosuite.blogspot.com/ --------------------------------------------------------------- 👍 **Don't forget to Like, Share, and Subscribe for more insightful tutorials! 🌐✨ #GoogleEarthEngine #ASTER #LithologicalMapping #RemoteSensing #GeologyMapping #GIS #GeospatialAnalysis #AtmosphericCorrection #DarkObjectSubtraction #GEE #ASTERImagery #RasterAnalysis #EarthObservation #MineralMapping #GISTutorial