HGPT2: An ERA5-Based Global Model to Estimate Relative Humidity
Abstract
:1. Introduction
2. Model Formulation
2.1. ERA5 Relative Humidity
- g0 = −2.8365744 × 103
- g1 = −6.028076559 × 103
- g2 = 1.954263612 × 101
- g3 = −2.737830188 × 10−2
- g4 = 1.6261698 × 10−5
- g5 = 7.0229056 × 10−10
- g6 = −1.8680009 × 10−13
- g7 = 2.7150305
- k0 = −5.8666426 × 103
- k1 = 2.232870244 × 101
- k2 = 1.39387003 × 10−2
- k3 = −3.4262402 × 10−5
- k4 = 2.7040955 × 10−8
- k5 = 6.7063522 × 10−1
- A0 = −1.6302041 × 10−1
- A1 = 1.8071570 × 10−3
- A2 = −6.7703064 × 10−6
- B3 = 8.5813609 × 10−9
- B0 = −5.9890467 × 101
- B1 = 3.4378043 × 10−1
- B2 = −7.7326396 × 10−4
- B3 = 6.3405286 × 10−7
- A0 = −6.0190570 × 10−2
- A1 = 7.3984060 × 10−4
- A2 = −3.0897838 × 10−6
- A3 = 4.3669918 × 10−9
- B0 = −9.4868712 × 101
- B1 = 7.2392075 × 10−1
- B2 = −2.1963437 × 10−3
- B3 = 2.4668279 × 10−6
2.2. HGPT2 Relative Humidity
2.3. HGPT2 Zenith Wet Delay
2.4. HGPT2 Precipitable Water Vapor
2.5. HGPT2 Height-Dependent Values Correction
3. Results and Discussion
4. Accuracy Assessment
5. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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GPT2W (5° × 5°) | GPT2W (1° × 1°) | GPT3 (5° × 5°) | GPT3 (1° × 1°) | HGPT2 (0.25° × 0.25°) | |
---|---|---|---|---|---|
RMSE (%) | 20.38 | 19.47 | 20.41 | 19.42 | 16.01 |
BIAS (%) | 2.65 | 1.71 | 2.65 | 1.67 | 1.42 |
ρ [−1, 1] | 0.26 | 0.28 | 0.25 | 0.27 | 0.61 |
FIRST RUN | SECOND RUN | |
---|---|---|
GNSS system | GPS | GPS |
Reference system | ITRF14 | ITRF14 |
Orbits | IGS Final | IGS Final |
Met obs source | GPT3 (1° × 1°) | Met-files (HGPT2) |
Ionospheric model | L3 1 | L3 1 |
Atmospheric tidal loading | Observation level 2 | Observation level 2 |
Ocean tide loading | FES2004 model 3 | FES2004 model 3 |
Dry mapping function | GMF 4 | GMF 4 |
Wet mapping function | GMF | GMF |
Elevation cutoff angle | 10° | 10° |
Interval zenith delays | every 2-hours | every 2-hours |
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Mateus, P.; Mendes, V.B.; Plecha, S.M. HGPT2: An ERA5-Based Global Model to Estimate Relative Humidity. Remote Sens. 2021, 13, 2179. https://doi.org/10.3390/rs13112179
Mateus P, Mendes VB, Plecha SM. HGPT2: An ERA5-Based Global Model to Estimate Relative Humidity. Remote Sensing. 2021; 13(11):2179. https://doi.org/10.3390/rs13112179
Chicago/Turabian StyleMateus, Pedro, Virgílio B. Mendes, and Sandra M. Plecha. 2021. "HGPT2: An ERA5-Based Global Model to Estimate Relative Humidity" Remote Sensing 13, no. 11: 2179. https://doi.org/10.3390/rs13112179