Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria

Estimation of Tropospheric Zenith Delay and Gradients

We have analyzed data from an experiment over the Madrid (Spain) area obtained from 5 GPS receivers and 3 Water Vapor Radiometers (WVR), in order to compare their retrievals of Tropospheric Slant Delays. For this purpose we have tted a simple gradient model to both types of data, using a Kalman lter to account for the temporal variability of the zenith and gradient parameters. We show that the ...

An improved global zenith tropospheric delay model

A New Zenith Tropospheric Delay Grid Product for Real-Time PPP Applications over China

Tropospheric delay is one of the major factors affecting the accuracy of electromagnetic distance measurements. To provide wide-area real-time high precision zenith tropospheric delay (ZTD), the temporal and spatial variations of ZTD with altitude were analyzed on the bases of the latest meteorological reanalysis product (ERA-Interim) provided by the European Center for Medium-Range Weather For...

GPS-Derived Tropospheric Delay Corrections to Differential InSAR Results

Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques have been recognised as an ideal tool for many ground deformation monitoring applications. However, the spatially and temporally variable delay of the radar signal propagating through the atmosphere is a major limitation to accuracy. The dominant factor to be considered is the tropospheric heterogeneity, which can lead to...

Use of GNSS SNR data to retrieve soil moisture and vegetation variables over a wheat crop

This work aims to estimate soil moisture and vegetation characteristics from Global Navigation Satellite System (GNSS) Signal to Noise Ratio (SNR) data using direct and reflected signals by the land surface surrounding a ground-based antenna. Observations are collected over a rainfed wheat field in southwestern France. The retrievals are compared with two independent reference datasets: in situ...