This map shows the geographic impact of Achim Helm's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Achim Helm with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Achim Helm more than expected).
This network shows the impact of papers produced by Achim Helm. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Achim Helm. The network helps show where Achim Helm may publish in the future.
Co-authorship network of co-authors of Achim Helm
This figure shows the co-authorship network connecting the top 25 collaborators of Achim Helm.
A scholar is included among the top collaborators of Achim Helm based on the total number of
citations received by their joint publications. Widths of edges
represent the number of papers authors have co-authored together.
Node borders
signify the number of papers an author published with Achim Helm. Achim Helm is excluded from
the visualization to improve readability, since they are connected to all nodes in the network.
All Works
18 of 18 papers shown
1.
Wickert, Jens, Maximilian Semmling, Achim Helm, et al.. (2016). GNSS Reflectometry: Recent activities at GFZ and selected international projects. Publication Database GFZ (GFZ German Research Centre for Geosciences).1 indexed citations
Helm, Achim, et al.. (2009). The ACES GNSS Subsystem and its Potential for Radio-Occultation and Reflectometry from the International Space Station. elib (German Aerospace Center).2 indexed citations
8.
Helm, Achim, et al.. (2008). Utilizing ocean reflected GPS L1 C/A and the new GPS L2C signals for Tsunami Detection from space: Possible small satellite constellations and the GORS instrument. elib (German Aerospace Center).2 indexed citations
Wickert, Jens, Christina Arras, C. O. Ao, et al.. (2008). Tapley CHAMP, GRACE, SAC-C, TerraSAR-X/Tandem-X, Science results, status and future prospects. Publication Database GFZ (GFZ German Research Centre for Geosciences).4 indexed citations
Helm, Achim, et al.. (2007). GORS - A GNSS Occultation, Reflectometry and Scatterometry Space Receiver. elib (German Aerospace Center). 2011–2021.10 indexed citations
15.
Helm, Achim, et al.. (2007). The GNSS Occultation, Reflectormetry and Scatterometry Space Receiver GORS: Current Status and Future Plans within GITEWS. elib (German Aerospace Center).1 indexed citations
Helm, Achim, et al.. (2001). Calibration of the shuttle radar topography mission X-SAR instrument using altimetry data. Publication Database GFZ (GFZ German Research Centre for Geosciences).1 indexed citations
Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive
bibliographic database. While OpenAlex provides broad and valuable coverage of the global
research landscape, it—like all bibliographic datasets—has inherent limitations. These include
incomplete records, variations in author disambiguation, differences in journal indexing, and
delays in data updates. As a result, some metrics and network relationships displayed in
Rankless may not fully capture the entirety of a scholar's output or impact.