Abstract
GPS satellites of Block IIR-M and the subsequent Blocks have the capability to redistribute the transmit power of the individual signal components, which is called flex power. This technology is used to prevent enemy jamming by increasing the power of the designed signal. It is of great importance to detect flex power since it has great impacts on differential code biases, phase shifts, and multiple access interference. Based on geodetic stations, stepwise enhancement in their carrier-to-noise density ratios (C/N0) can reflect the power changes caused by flex power. Thus, we propose a real-time detection method for GPS flex power based on C/N0 patterns. The patterns for 100 International GNSS Service stations uniformly distributed around the world are built according to their azimuths and elevations. In order to evaluate the performance of the proposed method, daily data with 30-s sampling in 2020 and real-time data with 1-s sampling in 2023 are adopted to detect flex power with the new method. Results of experiment show that the average false positive rate for real-time detection is around 10–6, and the true positive rate is 0.999479. The results confirm the effectiveness of our method for real-time flex power detection. Meanwhile, a new flex power mode is discovered in real-time detection experiments, which has the largest coverage area between longitudes 125°W and 180°E.
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Data availability
The datasets generated during and/or analyzed during the current study are available in the repository [http://gdc.cddis.eosdis.nasa.gov/pub/gnss/data/daily].
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Acknowledgements
We would like to thank the GNSS center of CDDIS (http://gdc.cddis.eosdis.nasa.gov/pub/gnss/) and iGMAS (http://www.igmas.org/Product/TreePage/tree/cate_id/37.html) for providing the raw GNSS data.
Funding
This work is supported by the National Natural Science Funds of China (42104013, 42225401), the Fundamental Research Funds for the Central Universities, Natural Science Funds of Shanghai (21ZR1465600), the Innovation Program of Shanghai Municipal Education Commission (2021–01-07–00-07-E00095), and the Scientific and Technological Innovation Plan from Shanghai Science and Technology Committee (22511103003).
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GM proposed the idea and designed and conducted the experiments; GM and HG analyzed the data, prepared the figures, and wrote the manuscript; HG and BL supervised the project and revised the manuscript. All authors joined discussions throughout the development and reviewed the manuscript.
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Meng, G., Ge, H. & Li, B. A real-time detection method for GPS flex power. GPS Solut 28, 111 (2024). https://doi.org/10.1007/s10291-024-01653-3
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DOI: https://doi.org/10.1007/s10291-024-01653-3