World navigation satellite techniques (GNSSs) present invaluable positioning information for numerous purposes, from on a regular basis navigation to scientific analysis. Tropospheric delays, brought on by the refractive properties of the environment, considerably impression the accuracy of GNSS positioning.
The standard practice of multiplying Zenith Tropospheric Delay (ZTD) by a Mapping Operate (MF) to derive SPD operates beneath an assumption of atmospheric isotropy, limiting precision in GNSS purposes.
In study revealed within the journal Satellite tv for pc Navigation, researchers from Shandong College of Science and Know-how introduce a novel idea that SPDs are non-isotropic with respect to azimuth angles, departing from conventional isotropic and anisotropic assumptions.
They utilized three completely different mapping capabilities and carried out evaluations at 5 Worldwide GNSS Service (IGS) stations, using the ray-tracing technique as a benchmark.
The examine in contrast SPD accuracy utilizing Vienna Mapping Operate 3 (VMF3) and located the smallest residual between VMF3-derived SPDs and ray-traced SPDs. Surprisingly, introducing a horizontal gradient correction for azimuth-dependent SPD variations confirmed no vital enchancment in accuracy.
Dr. Ying Xu, the main researcher of this examine, mentioned, “This revelation of non-isotropic tropospheric delays is a game-changer for high-precision GNSS purposes. By acknowledging and understanding these variations throughout azimuth angles, we are able to develop extra correct fashions, considerably enhancing the reliability of GNSS positioning techniques.”
The invention of non-isotropic habits in SPD throughout completely different azimuth angles highlights a pivotal side beforehand neglected in tropospheric delay modeling.
This perception challenges current methodologies and suggests the necessity for brand spanking new fashions that precisely characterize the complicated dynamics of the troposphere. Such developments are essential for purposes requiring high-precision GNSS positioning, similar to geodesy, navigation, and atmospheric sciences.
Extra data:
Ying Xu et al, An preliminary investigation of the non-isotropic function of GNSS tropospheric delay, Satellite tv for pc Navigation (2024). DOI: 10.1186/s43020-023-00122-5
Quotation:
Research uncovers the non-isotropic nature of tropospheric delay for high-precision GNSS positioning (2024, January 22)
retrieved 22 January 2024
from https://phys.org/information/2024-01-uncovers-isotropic-nature-tropospheric-delay.html
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