Soil moisture is an important variable in ecological, hydrological, and meteorological studies. An effective method for improving the accuracy of soil retrieval mutual supplementation multi-source data. The sensor configuration band settings different optical sensors lead to differences reflectivity inter-data, further resulting between vegetation indices. combination synthetic aperture radar (SAR) data with has been widely used retrieval. However, influence indices derived from sources on...

Global navigation satellite system reflectometry (GNSS-R) is a new remote sensing technique, which can be used to measure wide range of geophysical parameters. GNSS-R makes use the simultaneous reception direct transmission and coherent surface reflections GNSS signal with either single antenna or multiple separate antennas. This paper presents snow depth estimation method using combination pseudorange carrier phase dual-frequency signals. The proposed geometry-free not affected by...

Underground coal-mining-induced ground subsidence deformation is a common geological disaster impacting buildings, transportation and water supplies. Models predicting dynamically with high precision are important for the prevention of damage derived from subsidence. In this paper, Hook function utilized to develop model describing velocity due underground coal mining. Based on model, dynamic established by taking an integral model. Coefficients which depend maximum subsidence, time...

Snow depth and snow water equivalent (SWE) are two parameters for measuring snowfall. By exploiting the Global Navigation Satellite System reflectometry (GNSS-R) technique thousands of existing GNSS Continuous Operating Reference Stations (CORS) deployed in cryosphere, it is possible to improve temporal spatial resolutions SWE measurement. In this paper, a fusion model combining multi-satellite SNR (Signal Noise Ratio) estimations proposed, which uses peak spectral powers associated with...

Global navigation satellite system (GNSS) multipath signals received by a geodetic-quality GNSS receiver can be used to estimate the water content of soil around antenna. The direct from antenna are most valuable in geodetic measurement, such as positioning, navigation, control network, deformation monitoring, and so on. However, also captures reflected ground, which contain information surrounding environment, that useful about reflection surface inferred analyzing signal. This technique is...

In the last 20 years, reflected signal of Global Navigation Satellite System (GNSS) has been used for remotely sensing a series geophysical parameters, resulting in two GNSS based techniques: reflectometry (GNSS-R) and interferometric (GNSS-IR). this letter, refracted is first proposed to estimate near-surface soil moisture (SM). Amplitude will attenuate when penetrated into due refraction propagation soil. attenuation degree quantified as amplitude ratio (AR) direct signal. Two low-cost...

Underground coal mining-induced ground subsidence (or major vertical settlement) is a concern to the mining industry, government and people affected. Based on probability integral method, this paper presents new prediction method for predicting irregularly shaped area extraction-induced subsidence. Firstly, Delaunay triangulation used divide into series of triangular extraction elements. Then, elements within calculation are selected. Finally, Monte Carlo calculate element-induced The...

Two estimation methods using a dual GNSS (Global Navigation Satellite System) receiver system are proposed. The dual-frequency combination method combines the carrier phase observations of signals, whereas single-frequency pseudorange and signal, both which geometry-free strictly free effect ionospheric delay. Theoretical models established in offline to describe relationship between spectral peak frequency combined sequence antenna height. A field experiment was conducted recently data...

For the past 20 years, Global Navigation Satellite System reflectometry (GNSS-R) technology has successfully shown its potential for remote sensing of Earth’s surface, including ocean and land surfaces. It is a multistatic radar that uses GNSS signals reflected from surface to extract characteristics. Because numerous advantages such as low cost, multiple signal sources, all-day/weather high-spatiotemporal-resolution observations, this new attracted attention many researchers. One most...

In this paper, GNSS interferometric reflectometry (GNSS-IR) is firstly proposed to estimate ground surface subsidence caused by underground coal mining. Ground on the main direction of a seam described using probability integral model (PIM) with unknown parameters. Based laws reflection in geometric optics, signal-to-noise (SNR) observation for tilt surface, which results from differential points, derived. Semi-cycle SNR observations fitting method used determine phase series. Phase...

Comparisons between different global navigation satellite system (GNSS) signals and GNSS-reflectometry (GNSS-R) systems can provide valuable suggestions for future development of the GNSS-R instrument signal processing method. This article evaluates ocean altimetry performance multiple GNSS constellation using raw intermediate frequency data collected by Cyclone (CYGNSS) TechDemoSat-1 (TDS-1) satellites. Data used evaluation include observations GPS L1, Galileo E1, BDS B1 band signal. The...

Global Navigation Satellite System interferometric reflectometry is an emerging remote sensing technique that can be used to measure a wide range of geophysical parameters. In this letter, low-cost navigational GNSS chip and RHCP antenna were receive process the interference signal in winter wheat farmland. By simplifying crop as multi-layer equivalent mediums (EMs), characteristics SNR observations recorded by instrument analyzed. The confidence level Lomb-Scargle spectral analysis result...

Abstract As an indispensable surface parameter, soil moisture is of great significance for analyzing global water cycle, establishing the hydrological model and assessing drought. Due to differences in capability vegetation content (VWC) models based on different indices, influence VWC retrieval accuracy has not been effectively assessed. Therefore, suitability parameters obtained from established by indices accurate requires further investigation. In this study, were derived Sentinel‐2 data...

Ground subsidence caused by underground coalmining result in the formation of ponding water on ground surface. Monitoring surface level is crucial for studying hydrologic cycle mining areas. In this paper, we propose a combined technique using Global Navigation Satellite System Real-Time Kinematic (GNSS RTK) and GNSS Interferometric Reflectometry (GNSS-IR) to estimate areas coal mining. RTK used measure geodetic height antenna, which then converted into normal local anomaly model. GNSS-IR...

Soil moisture is fundamental to land surface hydrology, affecting flooding, groundwater recharge, and evapotranspiration. In this paper, a low-cost GNSS receiver used estimate soil the first time. A new estimation method based on SNR data proposed. The relationship between amplitude attenuation factor (AAF) of investigated by using in-situ observations at first. Then, retrieval AAF GPS collected over month in Chongqing, China was test proposed method. Based observations, 1 <sup...

It is important to determine the relationship between concentration of chlorophyll a (Chla) and inherent optical properties (IOPs) ocean water develop models algorithms that characterize biogeochemical estimate biological pumping carbon flux in this environment. However, previous studies reported relatively large variations particulate backscattering coefficient (b bp (λ)) Chla from more eutrophic high-latitude waters clear oligotrophic waters, especially oceanic areas where these two...