Monitoring the Water Vapor Content at High Spatio-Temporal Resolution Using a Network of Low-Cost Multi-GNSS Receivers

Abstract

The Global Navigation Satellite System (GNSS) has the capacity for remote sensing of water vapor content in the atmosphere. Post-processing of GNSS data can provide Integrated Water Vapor (IWV) with accuracies comparable to measurements of traditional sensors, i.e. water vapor radiometers. While GNSS meteorology benefits from thousands of permanent GNSS stations operating worldwide the spatial resolution of GNSS-derived IWV is limited to tens of kilometers. Further densification of GNSS networks is achievable with low-cost GNSS receivers. We investigated the feasibility of low-cost multi-GNSS receivers for monitoring IWV. The post-processing and the realtime solution are validated against 1) the results from a geodeticgrade GNSS receiver, 2) co-located water vapor radiometer, and 3) numerical weather model (NWM). Despite the high variability of the IWV during the validation period, the standard deviation of IWV differences with respect to the water vapor radiometer was 1.0 kg/m 2 and 1.5 kg/m 2 in post-processing and real-time, respectively. The city-scale variability of water vapor content in the atmosphere was monitored by a network of 16 low-cost GNSS receivers deployed in the city of Wroclaw, Poland. During rapidly changing weather conditions the disagreement between the low-cost GNSS-derived IWV field and the NWM reached up to 5.4 kg/m 2 and inter-station IWV differences exceeded 5 kg/m 2 . It has been demonstrated that low-cost GNSS receivers are reliable tools for precise determination of IWV, also in realtime. This study is the first to measure the water vapor content with a spatial resolution of single kilometers and to present a significantly diversified city-scale IWV field.

Parameterisation of the GNSS troposphere tomography domain with optimisation of the nodes’ distribution

“…Also, the topography of Wrocław city is rather flat which results in similar altitudes of all GNSS receivers within the network (maximum height difference between the stations equal to 25 m); it is a limiting factor in the tomographic reconstruction of the wet refractivity fields (Rohm andBosy 2009, 2011). In the paper by Marut et al (2022) it was proven that the low-cost GNSS receivers are able to provide 2-D information about water vapour distribution in the troposphere on the level of 1.0-1.5 kg m −2 IWV. It shows the ability of the low-cost receivers to provide water vapour distribution on the city scale, which was also shown in our research.…”

“…3). A detailed description of the receivers and the GNSS data processing strategy can be found in Marut et al (2022). The receivers are based on the u-blox high-precision GNSS module (ZED-F9P), microcomputer Raspberry Pi 3B+, and the GSM modem.…”

“…Recently, the low-cost GNSS receivers, based on mass-market chipsets capable of logging carrier phase measurements, were successfully applied in the troposphere profiling (Barindelli et al 2018;Bramanto et al 2018;Krietemeyer et al 2018). Since this approach is much less expensive than the geodetic-grade receivers, it provides an opportunity for troposphere monitoring on the kilometre scale by further densification of the GNSS networks (Marut et al 2022).…”

Investigating the Optimal Spatial Resolution for Assimilating GNSS PWV into an NWP System to Improve the Accuracy of Humidity Field

“…A S AN emerging and novel method for the sensing of atmospheric parameters, the ground-based global navigation satellite systems (GNSSs) tropospheric sounding technique has undergone unprecedented development in recent decades [1], [2], [3], [4]. Multiple products obtained from this technique, e.g., zenith total delay (ZTD) and precipitable water vapor (PWV), are known to have the advantageous features of high accuracy, high spatiotemporal resolution, all-weather, low cost, and free of instrumental bias [5], [6], [7], [8], [9]. Therefore, this advanced technique has offered strong data support and opened new opportunities to enhance our understanding of atmospheric conditions, climate phenomena, and weather extremes [10], [11], [12], [13].…”

Mpg-Net: A Low-Cost, Multi-Purpose Gnss Co-Location Station Network for Environmental Monitoring

“…Ste ¸pniak and Paziewski [37] confirmed these findings by comparing solutions from the ZED-F9P using different antenna types to tropospheric delays from ray-tracing. In a recent study, Marut et al [38] showed the usability of the ZED-F9P for retrieval of ZTD and integrated water vapor (IWV) in a very dense network, covering the city of Wroclaw, Poland. Validation of their results using estimates from geodetic-grade GNSS receivers and a co-located water vapor radiometer showed satisfactory performance of the proposed station setup.…”