Next Article in Journal
Active Semi-Supervised Random Forest for Hyperspectral Image Classification
Next Article in Special Issue
Hybrid Chlorophyll-a Algorithm for Assessing Trophic States of a Tropical Brazilian Reservoir Based on MSI/Sentinel-2 Data
Previous Article in Journal
Assessment of Canopy Porosity in Avocado Trees as a Surrogate for Restricted Transpiration Emanating from Phytophthora Root Rot
Open AccessArticle

Modelling the Altitude Dependence of the Wet Path Delay for Coastal Altimetry Using 3-D Fields from ERA5

1
Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
2
Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, 4450-208 Matosinhos, Portugal
*
Author to whom correspondence should be addressed.
Remote Sens. 2019, 11(24), 2973; https://doi.org/10.3390/rs11242973
Received: 14 October 2019 / Revised: 29 November 2019 / Accepted: 9 December 2019 / Published: 11 December 2019
(This article belongs to the Special Issue Remote Sensing of Coastal and Inland Waters)
Wet path delay (WPD) for satellite altimetry has been provided from external sources, raising the need of converting this value between different altitudes. The only expression available for this purpose considers the same altitude reduction, irrespective of geographic location and time. The focus of this study is the modelling of the WPD altitude dependence, aiming at developing improved expressions. Using ERA5 pressure level fields (2010–2013), WPD vertical profiles were computed globally. At each location and for each vertical profile, an exponential function was fitted using least squares, determining the corresponding decay coefficient. The time evolution of these coefficients reveals regions where they are highly variable, making this modelling more difficult, and regions where an annual signal exists. The output of this modelling consists of a set of so-called University of Porto (UP) coefficients, dependent on geographic location and time. An assessment with ERA5 data (2014) shows that for the location where the Kouba coefficient results in a maximum Root Mean Square (RMS) error of 3.2 cm, using UP coefficients this value is 1.2 cm. Independent comparisons with WPD derived from Global Navigation Satellite Systems and radiosondes show that the use of UP coefficients instead of Kouba’s leads to a decrease in the RMS error larger than 1 cm. View Full-Text
Keywords: satellite radar altimetry; wet path delay; altitude dependence modelling; coastal zones; ERA5 satellite radar altimetry; wet path delay; altitude dependence modelling; coastal zones; ERA5
Show Figures

Graphical abstract

MDPI and ACS Style

Vieira, T.; Fernandes, M.J.; Lázaro, C. Modelling the Altitude Dependence of the Wet Path Delay for Coastal Altimetry Using 3-D Fields from ERA5. Remote Sens. 2019, 11, 2973. https://doi.org/10.3390/rs11242973

AMA Style

Vieira T, Fernandes MJ, Lázaro C. Modelling the Altitude Dependence of the Wet Path Delay for Coastal Altimetry Using 3-D Fields from ERA5. Remote Sensing. 2019; 11(24):2973. https://doi.org/10.3390/rs11242973

Chicago/Turabian Style

Vieira, Telmo; Fernandes, M. J.; Lázaro, Clara. 2019. "Modelling the Altitude Dependence of the Wet Path Delay for Coastal Altimetry Using 3-D Fields from ERA5" Remote Sens. 11, no. 24: 2973. https://doi.org/10.3390/rs11242973

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop