Least travel time ray tracer version 2 (LTT v2) adapted to the grid geometry of the OpenIFS atmospheric model

Guardado en:
Bibliografiske detaljer
Udgivet i:Geoscientific Model Development vol. 18, no. 16 (2025), p. 5015
Hovedforfatter: Vasiuta, Maksym
Andre forfattere: Angel Navarro Trastoy, Motlaghzadeh, Sanam, Tuppi, Lauri, Mayer-Gürr, Torsten, Järvinen, Heikki
Udgivet:
Copernicus GmbH
Fag:
Online adgang:Citation/Abstract
Full Text
Full Text - PDF
Tags: Tilføj Tag
Ingen Tags, Vær først til at tagge denne postø!

MARC

LEADER 00000nab a2200000uu 4500
001 3240392544
003 UK-CbPIL
022 |a 1991-962X 
022 |a 1991-9603 
024 7 |a 10.5194/gmd-18-5015-2025  |2 doi 
035 |a 3240392544 
045 2 |b d20250101  |b d20251231 
084 |a 123629  |2 nlm 
100 1 |a Vasiuta, Maksym  |u Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 
245 1 |a Least travel time ray tracer version 2 (LTT v2) adapted to the grid geometry of the OpenIFS atmospheric model 
260 |b Copernicus GmbH  |c 2025 
513 |a Journal Article 
520 3 |a Electromagnetic signals commonly used in geodetic applications, such as the Global Navigation Satellite System (GNSS), undergo bending and delay in the neutral gas atmosphere of the Earth. The least travel time (LTT) concept is one of the approaches to model signal slant delays via a ray tracing (RT) procedure. In this study, we developed an LTT-based RT algorithm (LTT v2), where the three-dimensional refractivity field of the atmosphere is based on the atmospheric model data. This representation is complete in a sense that the domain of the RT conforms to the native grid geometry of the atmospheric model. In principle, the LTT-based RT algorithm is seen as an extension of an atmospheric model for signal delay evaluation. The atmospheric states are generated using a global numerical weather prediction model, the Open Integrated Forecast System of the European Centre for Medium-Range Weather Forecasts. In the LTT v2 model, some physical and numerical approximations are improved compared to the original implementation, called “LTT v1”. We compare the slant delays products of the two models. Additionally, a comparable modelling setup is created with the state-of-the-art VieVS Ray Tracer (RADIATE). The skill of slant delay estimation is assessed using metrics that are indicative of the quality of GNSS products derived using the GROOPS (Gravity Recovery Object Oriented Programming System) orbit solver software toolkit of the Graz University of Technology. The metrics used are GNSS orbit midnight discontinuities (MDs) and residuals of ground station precise positioning with respect to the IGS14 reference. Employment of slant delay products of the LTT RT algorithm in GNSS processing shows similar performance with v1 and v2. The GNSS orbit MDs are reduced by around 3 % when using the LTT v2 model, while root-mean-square residuals of ground station precise positioning are 5 % lower with LTT v1. The consistency of both metrics is improved slightly using LTT v2, as seen by the metrics' standard deviation values. Intercomparison with RADIATE indicates significantly better performance of LTT v2, which we attribute entirely to the much larger amount and lossless utilization of weather model data as input to LTT v2 versus RADIATE. 
653 |a Weather forecasting 
653 |a Global weather 
653 |a Atmospheric models 
653 |a Navigation 
653 |a Atmosphere 
653 |a Travel time 
653 |a Refractivity 
653 |a Numerical weather forecasting 
653 |a Optics 
653 |a Prediction models 
653 |a Asymmetry 
653 |a Propagation 
653 |a Global positioning systems--GPS 
653 |a Tracers 
653 |a Earth atmosphere 
653 |a Algorithms 
653 |a Intercomparison 
653 |a Satellites 
653 |a Ground stations 
653 |a Object oriented programming 
653 |a Signal delay 
653 |a Global navigation satellite system 
653 |a Software 
653 |a Weather 
653 |a Navigation satellites 
653 |a Data assimilation 
653 |a Deformation 
653 |a Ray tracing 
653 |a Navigation systems 
653 |a Refractive index 
653 |a Navigational satellites 
653 |a Neutral gases 
653 |a Design 
653 |a Medium-range forecasting 
653 |a Environmental 
700 1 |a Angel Navarro Trastoy  |u Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 
700 1 |a Motlaghzadeh, Sanam  |u Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 
700 1 |a Tuppi, Lauri  |u Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 
700 1 |a Mayer-Gürr, Torsten  |u Institute of Geodesy, Graz University of Technology, Graz, Austria 
700 1 |a Järvinen, Heikki  |u Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland 
773 0 |t Geoscientific Model Development  |g vol. 18, no. 16 (2025), p. 5015 
786 0 |d ProQuest  |t Engineering Database 
856 4 1 |3 Citation/Abstract  |u https://www.proquest.com/docview/3240392544/abstract/embedded/ZKJTFFSVAI7CB62C?source=fedsrch 
856 4 0 |3 Full Text  |u https://www.proquest.com/docview/3240392544/fulltext/embedded/ZKJTFFSVAI7CB62C?source=fedsrch 
856 4 0 |3 Full Text - PDF  |u https://www.proquest.com/docview/3240392544/fulltextPDF/embedded/ZKJTFFSVAI7CB62C?source=fedsrch