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Research about Germany, United States

Source-linked reports with geographic coverage including Germany, United States.

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Topography-aware registration refinement of Landsat 8/9 L1TP products with Sentinel-2 L1C and NAIP orthoimages

Satellite orthoimage products are widely available, yet residual geometric misregistration across independently processed products remains common, limiting their direct interoperability for multi-source and multi-temporal analysis. This paper introduces a residual Multi-Layer Perceptron (MLP)–based, topography-aware framework to further increase the registration quality of existing orthoimages based on dense matching without requiring any sensor-specific metadata or physical imaging parameters. We evaluate our approach by precisely co-registering 26 Landsat 8/9 Collection 2 Level-1 Terrain Precision (L1TP) scenes across Indiana (USA) and Berlin (Germany) with Sentinel-2 L1C and National Agriculture Imagery Program (NAIP) orthoimages. The baseline Landsat misregistration to Sentinel-2 or NAIP typically ranges from 3 to 10 m, which is reduced to 2–4 m after applying our MLP-based refinement, outperforming conventional polynomial and Rational Polynomial Coefficient (RPC) models. Further empirical evaluation demonstrates that consistent registration precision can be achieved across various terrain datasets; specifically, 30 m global digital elevation models (DEMs) yield comparable performance to that of high resolution (1–10 m) national or regional DEMs. The developed MLP approach provides a precise and reliable framework that transcends Landsat-specific tasks. It is readily adaptable to other registration applications requiring high-fidelity geometric alignment and consistent integration of heterogeneous image sources.

Indiana

Deep hydraulic fracturing stress measurements in the KTB (Germany) and Cajon Pass (USA) Scientific Drilling Projects: A summary

The determination of in situ stresses along deep vertical profiles was declared a key issue for two scientific deep drilling projects: the German Continental Deep Drilling Project (KTB) situated in northeast Bavaria in an area of complex variscian thrust tectonics and the CAJON PASS Project, located only about 4 km from the San Andreas Fault Zone In southern California. In the KTB project 7 successful hydrofrac stress measurements could be completed in a 4 km deep pilot hole between 0.8 to 3.0 km. At the Cajon Pass site a series of 23 hydrofrac stress measurements was performed in 2 wells between 0.9 to 3.5 km.

Bavaria, California