Analysis of the differences between GPS radio occultation and radiosonde atmosphere profiles in Egypt

Ahmed, I.; El-Fatah, Mohamed Amin Abd; Mousa, Ashraf; El-Fiky, Gamal

doi:10.1016/j.ejrs.2022.02.006

Cited by 4 publications

(4 citation statements)

References 11 publications

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“…The WVP content showed minimal differences (0.00 mb), while the refractivity exhibited a slight increase of 0.01 in PlanetiQ. However, the present findings should be considered in light of the single-profile comparison results presented by [15], which highlighted differences in relative errors between datasets. While our study revealed subtle distinctions in atmospheric conditions, Ref.…”

Section: Planetiq-cosmic Profiles Comparison 421 Single Profile Compa...mentioning

confidence: 48%

“…While our study revealed subtle distinctions in atmospheric conditions, Ref. [15] found mean absolute differences for pressure, temperature, WVP, and refractivity and calculated relative errors as percentages. Notably, their analysis indicated that the difference percentage for WVP was 62%, suggesting significant variations in humidity profiles between datasets.…”

Section: Planetiq-cosmic Profiles Comparison 421 Single Profile Compa...mentioning

confidence: 49%

“…Furthermore, studies have elucidated differences between GPS RO and radiosonde atmosphere profiles, providing valuable insights into atmospheric variabilities. Particularly, research in regions like Egypt, led by [15], contributes to our understanding of atmospheric dynamics in specific geographical contexts. These comparative analyses collectively contribute to advancing our comprehension of atmospheric phenomena and optimizing the utilization of GNSS-RO data in various scientific applications.…”

Section: Literature Reviewmentioning

confidence: 99%

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PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

Ahmed,

Alheyf,

Yamany

2024

Applied Sciences

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Radio Occultation (RO) is pivotal for profiling the neutral and ionized atmosphere, with the PlanetiQ mission, via its GNOMES satellites, striving to establish an advanced atmospheric observing system. However, an assessment of the spatiotemporal distributions of PlanetiQ observations and comparisons with reliable datasets are lacking. This study addresses this gap by examining the temporal and spatial distribution of RO observations from PlanetiQ during its initial 198 operational days in 2023, alongside comparisons with COSMIC and Numerical Weather Prediction (NWP) models. Data from GN02, GN03, and GN04 satellites, yielding 1099, 1313, and 1843 RO events per day, respectively, were analyzed. The satellite constellation’s observations demonstrate a generally well-distributed pattern, albeit minor deficiencies in equatorial and polar regions. Single-profile comparisons with COSMIC data reveal strong correlations for pressure, temperature, Water Vapor Pressure (WVP), and refractivity profiles, with temperature exhibiting larger variations (RMSE = 1.24 °C). Statistical analyses confirm statistically insignificant differences between the PlanetiQ and COSMIC profiles at the same spatio-temporal coordinates. Comparisons with NWP models show slight differences with GFS, with overall RMSE values of 0.23 mb (WVP), 0.6 mb (pressure), 1.3 (refractivity), and 1.5 °C (temperature). However, assessments against GFS/ECMWF models indicate overall compatibility, with insignificant differences between PlanetiQ profiles and model observations.

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Section: Planetiq-cosmic Profiles Comparison 421 Single Profile Compa...mentioning

confidence: 48%

Section: Planetiq-cosmic Profiles Comparison 421 Single Profile Compa...mentioning

confidence: 49%

Section: Literature Reviewmentioning

confidence: 99%

See 1 more Smart Citation

PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

Ahmed,

Alheyf,

Yamany

2024

Applied Sciences

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“…Furthermore, studies have elucidated differences between GPS RO and radiosonde atmosphere profiles, providing valuable insights into atmospheric variabilities. Particularly, research in regions like Egypt, led by [7], contributes to our understanding of the atmospheric dynamics in specific geographical contexts. These comparative analyses collectively contribute to advancing our comprehension of atmospheric phenomena and optimizing the utilization of GNSS-RO data in various scientific applications.…”

Section: Literature Reviewmentioning

confidence: 99%

PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

Ahmed,

Alheyf,

Yamany

2024

Preprint

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Radio Occultation (RO) is pivotal for profiling the neutral and ionized atmosphere, with the PlanetiQ mission, via its GNOMES satellites, striving to establish an advanced atmospheric observing system. However, an assessment of the spatiotemporal distributions of PlanetiQ observations and comparisons with reliable datasets are lacking. This study addresses this gap by examining the temporal and spatial distribution of RO observations from PlanetiQ during its initial 198 operational days in 2023, alongside comparisons with COSMIC and Numerical Weather Prediction (NWP) models. Data from GN02, GN03, and GN04 satellites, yielding 1099, 1313, and 1843 RO events per day respectively, were analyzed. The satellite constellation's observations demonstrate a generally well-distributed pattern, albeit minor deficiencies in equatorial and polar regions. Single-profile comparisons with COSMIC data reveal strong correlations for pressure, temperature, Water Vapor Pressure (WVP), and refractivity profiles, with temperature exhibiting larger variations (RMSE = 1.24°C). Statistical analyses confirm statistically insignificant differences between PlanetiQ and COSMIC profiles at the same spatio-temporal coordinates. Comparisons with NWP models show slight differences with GFS, with overall RMSE values of 0.23 mb (WVP), 0.6 mb (pressure), 1.3 (refractivity), and 1.5°C (temperature). However, assessments against GFS/ECMWF models indicate overall compatibility, with insignificant differences between PlanetiQ profiles and models observations.

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Comparative performance of PPP software packages in atmospheric delay estimation using GNSS data

Nagib,

Abdelfatah,

Mousa

et al. 2024

Journal of Applied Geodesy

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This study utilizes Precise Point Positioning (PPP) for accurate GNSS-based positioning with a single receiver. Seven PPP techniques (GAPS, APPS, CSRS, Magic-GNSS, gLAB, Pride, GAMP) are evaluated for zenith tropospheric delay (ZTD) estimates, comparing them with Radiosonde (RS) and Radio Occultation (RO) data from the same day (36th in 2014). RO data is categorized based on RO Events (ROE) – GNSS observation distances (10 km, 50 km, 50:100 km), while RS data is limited to three stations (ASWN, FARF, PHLW). Generally, the differences among PPP techniques are within 5 cm, except for PRIDE-PPPAR, which exhibits semi-constant zenith wet delay (ZWD) values. Root Mean Square (RMS) and t-test comparisons with RO data reveal that APPS has the lowest RMS values for ZWD at 10 km, while CSRS-PPP performs well with increasing distance. Magic-GNSS demonstrates the highest RMS values at 10: 50 km, while APPS at 50:100 km. RMS values typically increase with greater ROE-GNSS distances, except for Magic-GNSS, which decreases. t-tests indicate statistically insignificant differences across PPP techniques, except for APPS and gLAB in the 50:100 km case. Comparisons with RS data indicate that CSRS-PPP achieves the lowest RMS values for ZWD at ASWN and PHLW, while Magic-GNSS and CSRS-PPP excel at FARF. However, Magic-GNSS, GAMP, GAPS, and Pride yield the highest RMS values at ASWN (00:00), (12:00), FARF, and PHLW, respectively. t-tests show statistically insignificant differences across PPP techniques for the three stations, except for APPS and Pride at ASWN and gLAB at PHLW. These findings demonstrate that CSRS-PPP consistently provides reliable ZWD assessments across various conditions, contributing to enhanced accuracy in GNSS-based atmospheric studies. The comparison of PPP techniques offers valuable insights into the strengths and limitations of each method, with implications for improving atmospheric modeling, positioning applications, and broader GNSS-based research in weather forecasting and climate monitoring.

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Analysis of the differences between GPS radio occultation and radiosonde atmosphere profiles in Egypt

Cited by 4 publications

References 11 publications

PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

PlanetiQ Radio Occultation: Preliminary Comparative Analysis of Neutral Profiles vs. COSMIC and NWP Models

Comparative performance of PPP software packages in atmospheric delay estimation using GNSS data

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