# AetherGeo: A Spectral Analysis Interface for Geologic Mapping
## 5 Discussion  
The current version of AetherGeo is mainly intended to work with geospatial data, but the visualization is pixel-based and not georeferenced. For the results generated by any analysis to have spatial meaning, all necessary metadata for georeferentiation is saved in conjunction with any new layer created. Therefore, all the output images generated by AetherGeo can be later analyzed in a GIS environment. Compared with other alternatives, especially other free, open-source projects [8; 9; 10; 11], it is important to highlight that AetherGeo provides the user with extensive tools for endmember extraction from a 3D point cloud, something that the other free software alternatives described do not offer. Other contributions of AetherGeo for state-of-the-art geological applications are as follows: (i) AetherGeo offers per-band significance graphs for each dimensionality reduction technique; (ii) it is one of the few software that offers the NMF algorithm for dimensionality reduction, having potential for geological application; (iii) AetherGeo is the only software that allows intuitive and interactive 3D point cloud extraction with embedding resulting from UMAP, which provides great capabilities to preserve local and global data structure [46]; (iv) it provides density-based clustering for image classification and endmember extraction; (v) AetherGeo offers a 2D plot function that enables the user to select pixels based on their associated values. Figure 11 of Appendix B shows a more detailed workflow using multiple functions to achieve image classification based on an endmember extracted from a given image and only using such an image as a starting point (without previous information), highlighting how multiple functions can be used together to achieve a final classification result, and also serves as a guide for anyone learning how to use the software. Additionally, all the tools in AetherGeo are provided without any dependency on proprietary packages or software, and the user can modify any of its components without  
Figure 9: (**a**) Parameter and layer selection menu. (**b**) Clustering results before saving the image. any proprietary license. In this way, it differs from an available alternative [10] that runs on MATLAB, which requires a full license. AetherGeo, built in Python, provides access to state-of-the-art libraries, especially for machine learning. Though the current version does not include any specific algorithm for noise correction, we intend to explore some alternatives currently present in the literature [20; 21; 22] in the future and subsequently add some functions to the preprocessing group regarding such matters. Regarding the potential for geological applications, the capabilities of AetherGeo software can be expanded to include more than satellite data, such as UAV, airborne, and laboratory data. Since the software is developed to extract information from images, the scale of work is defined by the capabilities to acquire corrected images, which, in the case of particular sensors for UAV, airborne, and laboratory applications, may require specific preprocessing with software developed for the specific sensor. Even though the image analysis functions were tested in images containing data from the \"visible and near-infrared\" (VNIR) and \"short-wave infrared\" (SWIR), they can also be tested and applied to other spectral ranges. Due to the flexibility of working with different spectral ranges and image scales, we believe this software provides helpful analysis tools across different geological applications. Additionally, since hyperspectral data can be helpful in many areas of expertise, the hyperspectral image analysis features available in AetherGeo can be explored by specialists in other fields of study. Another topic that has been discussed extensively in the literature is that even though many algorithms have been developed, they tend to be difficult to test due to either limitations in testing data or limitations in access and applicability by other experts.