GiRsnow: an open-source software for snow depth retrievals using GNSS interferometric reflectometry


Snow is an important water resource that plays a critical role in the global climate and hydrological cycle. Thus, Global Navigation Satellite System Interferometric Reflectometry (GNSS-IR) has emerged as a new remote sensing technology for monitoring snow depth. We developed the snow parameter processing software GiRsnow, based on GNSS-IR tools and a MATLAB environment, to obtain robust and effective retrievals. That tool allows users to check the data quality, draw reflection point trajectory and Fresnel zone, retrieve snow depth using signal-to-noise ratio (SNR) observations or geometry-free linear carrier phase combination (termed L4) observations, and display the results based on the time and space domain. We conducted two experiments at the Plate Boundary Observation site RN86 and GPS Earth Observation Network (GEONET) site 020877 to validate the performance of the software. Our results demonstrate that GiRsnow can process multi-constellation and multi-frequency GNSS data and obtain robust and effective results through quality control and a grid model to account for topography effects.

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Data Availability

The data used to support the findings of this study are available from the provided URL.


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We are grateful to Geospatial Information Authority of Japan (GSI) and University NAVSTAR Consortium (UNAVCO) for providing experimental data, and we thank Kristine Larson, Carolyn Roesler, Berkay Bahadur, and many others who have provided open access to MATLAB code. The research was funded by Chang’an University (Xi’an, China) through the National Key R&D Program of China (2019YFC1509802, 2020YFC1512000, 2018YFC1505102); Natural Science Foundation of China projects (NSFC) (Nos: 42074041, 41731066, 42074041); Shaanxi Natural Science Research Program (No: 2020JM-227); State Key Laboratory of Geo-Information Engineering(SKLGIE2019-Z-2-1); Fundamental Research Funds for the Central Universities (Nos. 300102269201, 300102299206).

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Correspondence to Shuangcheng Zhang.

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Zhang, S., Peng, J., Zhang, C. et al. GiRsnow: an open-source software for snow depth retrievals using GNSS interferometric reflectometry. GPS Solut 25, 55 (2021).

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  • Snow depth
  • Quality control
  • Grid model