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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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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The GPS Tool Box is a column dedicated to highlighting algorithms and source code utilized by GPS engineers and scientists. If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail it to us at firstname.lastname@example.org. To comment on any of the source code discussed here, or to download source code, visit our website at http://www.ngs.noaa.gov/gps-toolbox. This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada.
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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). https://doi.org/10.1007/s10291-021-01096-0
- Snow depth
- Quality control
- Grid model