Next Article in Journal
On Capabilities of Tracking Marine Surface Currents Using Artificial Film Slicks
Previous Article in Journal
L-Band Passive Microwave Data from SMOS for River Gauging Observations in Tropical Climates
Article Menu
Issue 7 (April-1) cover image

Export Article

Open AccessArticle
Remote Sens. 2019, 11(7), 839; https://doi.org/10.3390/rs11070839

Sea Surface Ka-Band Doppler Measurements: Analysis and Model Development

1
Remote Sensing Department, Marine Hydrophysical Institute of RAS, 2 Kapitanskaya St., 299011 Sevastopol, Russia
2
Satellite Oceanography Laboratory, Russian State Hydrometeorological University, 98 Malookhtinskiy Pr., 195196 St-Petersburg, Russia
3
Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20740, USA
4
Spatial and Physical Oceanography Laboratory, Institut Français de Recherche pour l’Exploitation de la Mer, 29280 Plouzané, France
*
Author to whom correspondence should be addressed.
Received: 26 February 2019 / Revised: 1 April 2019 / Accepted: 4 April 2019 / Published: 8 April 2019
(This article belongs to the Section Ocean Remote Sensing)
  |  
PDF [9922 KB, uploaded 8 April 2019]
  |  

Abstract

Multi-year field measurements of sea surface Ka-band dual-co-polarized (vertical transmit–receive polarization (VV) and horizontal transmit–receive polarization (HH)) radar Doppler characteristics from an oceanographic platform in the Black Sea are presented. The Doppler centroid (DC) estimated using the first moment of 5 min averaged spectrum, corrected for measured sea surface current, ranges between 0 and ≈1 m/s for incidence angles increasing from 0 to 70 . Besides the known wind-to-radar azimuth dependence, the DC can also depend on wind-to-dominant wave direction. For co-aligned wind and waves, a negative crosswind DC residual is found, ≈−0.1 m/s, at ≈20 incidence angle, becoming negligible at ≈ 60 , and raising to, ≈+0.5 m/s, at 70 . For our observations, with a rather constant dominant wave length, the DC is almost wind independent. Yet, results confirm that, besides surface currents, the DC encodes an expected wave-induced contribution. To help the interpretation, a two-scale model (KaDOP) is proposed to fit the observed DC, based on the radar modulation transfer function (MTF) previously developed for the same data set. Assuming universal spectral shape of energy containing sea surface waves, the wave-induced DC contribution is then expressed as a function of MTF, significant wave height, and wave peak frequency. The resulting KaDOP agrees well with independent DC data, except for swell-dominated cases. The swell impact is estimated using the KaDOP with a modified empirical MTF. View Full-Text
Keywords: radar; scatterometer; ocean; backscatter; Doppler shift; Doppler centroid; sea surface current; wind drift; modulation; transfer function; empirical model radar; scatterometer; ocean; backscatter; Doppler shift; Doppler centroid; sea surface current; wind drift; modulation; transfer function; empirical model
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Yurovsky, Y.Y.; Kudryavtsev, V.N.; Grodsky, S.A.; Chapron, B. Sea Surface Ka-Band Doppler Measurements: Analysis and Model Development. Remote Sens. 2019, 11, 839.

Show more citation formats Show less citations formats

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

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Remote Sens. EISSN 2072-4292 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top