Publications
>
Review

GNSS-reflectometry and remote sensing of soil moisture: A review of measurement techniques, methods, and applications

Publicated to:Remote Sensing. 12 (4): 614- - 2020-02-01 12(4), DOI: 10.3390/rs12040614

Authors: Edokossi, Komi; Calabia, Andres; Jin, Shuanggen; Molina, Inigo

Affiliations

Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China - Author
Nanjing Univ Informat Sci & Technol, Sch Remote Sensing & Geomat Engn, Nanjing 210044, Peoples R China - Author
Nanjing University of Information Science and Technology - Author
Shanghai Astronomical Observatory Chinese Academy of Sciences - Author
Univ Politecn Madrid, Sch Land Surveying Geodesy & Mapping Engn, South Campus, Madrid 28031, Spain - Author
Universidad Politécnica de Madrid - Author
See more

Abstract

© 2020 by the authors. The understanding of land surface-atmosphere energy exchange is extremely important for predicting climate change and weather impacts, particularly the influence of soil moisture content (SMC) on hydrometeorological and ecological processes, which are also linked to human activities. Unfortunately, traditional measurement methods are expensive and cumbersome over large areas, whereas measurements from satellite active and passive microwave sensors have shown advantages for SMC monitoring. Since the launch of the first passive microwave satellite in 1978, more and more progresses have been made in monitoring SMC from satellites, e.g., the Soil Moisture Active and Passive (SMAP) and Soil Moisture and Ocean Salinity (SMOS) missions in the last decade. Recently, new methods using signals of opportunity have been emerging, highlighting the Global Navigation Satellite Systems-Reflectometry (GNSS-R), which has wide applications in Earth's surface remote sensing due to its numerous advantages (e.g., revisiting time, global coverage, low cost, all-weather measurements, and near real-time) when compared to the conventional observations. In this paper, a detailed review on the current SMC measurement techniques, retrieval approaches, products, and applications is presented, particularly the new and promising GNSS-R technique. Recent advances, future prospects and challenges are given and discussed.

Keywords

Active and passive microwaveEmpirical-modelGnss-rL-band radiometryMicrowave dielectric behaviorMulti-incidenceRadar-scatteringSemiempirical modelSmall-slope approximationSoil moistureSurface-roughnessVegetation coverWater-content estimation

Quality index

Bibliometric impact. Analysis of the contribution and dissemination channel

The work has been published in the journal Remote Sensing due to its progression and the good impact it has achieved in recent years, according to the agency WoS (JCR), it has become a reference in its field. In the year of publication of the work, 2020, it was in position 27/200, thus managing to position itself as a Q1 (Primer Cuartil), in the category Geosciences, Multidisciplinary.

From a relative perspective, and based on the normalized impact indicator calculated from World Citations provided by WoS (ESI, Clarivate), it yields a value for the citation normalization relative to the expected citation rate of: 2.11. This indicates that, compared to works in the same discipline and in the same year of publication, it ranks as a work cited above average. (source consulted: ESI Nov 14, 2024)

This information is reinforced by other indicators of the same type, which, although dynamic over time and dependent on the set of average global citations at the time of their calculation, consistently position the work at some point among the top 50% most cited in its field:

  • Weighted Average of Normalized Impact by the Scopus agency: 4.94 (source consulted: FECYT Feb 2024)
  • Field Citation Ratio (FCR) from Dimensions: 15.53 (source consulted: Dimensions Jun 2025)

Specifically, and according to different indexing agencies, this work has accumulated citations as of 2025-06-10, the following number of citations:

  • WoS: 56
  • Scopus: 82
  • OpenCitations: 64

Impact and social visibility

From the perspective of influence or social adoption, and based on metrics associated with mentions and interactions provided by agencies specializing in calculating the so-called "Alternative or Social Metrics," we can highlight as of 2025-06-10:

  • The use, from an academic perspective evidenced by the Altmetric agency indicator referring to aggregations made by the personal bibliographic manager Mendeley, gives us a total of: 129.
  • The use of this contribution in bookmarks, code forks, additions to favorite lists for recurrent reading, as well as general views, indicates that someone is using the publication as a basis for their current work. This may be a notable indicator of future more formal and academic citations. This claim is supported by the result of the "Capture" indicator, which yields a total of: 128 (PlumX).

With a more dissemination-oriented intent and targeting more general audiences, we can observe other more global scores such as:

  • The Total Score from Altmetric: 8.65.
  • The number of mentions on the social network Facebook: 1 (Altmetric).
  • The number of mentions on the social network X (formerly Twitter): 13 (Altmetric).

It is essential to present evidence supporting full alignment with institutional principles and guidelines on Open Science and the Conservation and Dissemination of Intellectual Heritage. A clear example of this is:

  • The work has been submitted to a journal whose editorial policy allows open Open Access publication.

Leadership analysis of institutional authors

This work has been carried out with international collaboration, specifically with researchers from: China.

There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: Last Author (MOLINA SANCHEZ, IÑIGO).

the author responsible for correspondence tasks has been CALABIA AIBAR, ANDRES.