We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Validation of Jason-1 and Envisat Remotely Sensed Wave Heights.
- Authors
Durrant, Tom H.; Greenslade, Diana J. M.; Simmonds, Ian
- Abstract
Satellite altimetry provides an immensely valuable source of operational significant wave height (Hs) data. Currently, altimeters on board Jason-1 and Envisat provide global Hs observations, available within 3–5 h of real time. In this work, Hs data from these altimeters are validated against in situ buoy data from the National Data Buoy Center (NDBC) and Marine Environmental Data Service (MEDS) buoy networks. Data cover a period of three years for Envisat and more than four years for Jason-1. Collocation criteria of 50 km and 30 min yield 3452 and 2157 collocations for Jason-1 and Envisat, respectively. Jason-1 is found to be in no need of correction, performing well throughout the range of wave heights, although it is notably noisier than Envisat. An overall RMS difference between Jason-1 and buoy data of 0.227 m is found. Envisat has a tendency to overestimate low Hs and underestimate high Hs. A linear correction reduces the RMS difference by 7%, from 0.219 to 0.203 m. In addition to wave height–dependent biases in the altimeter Hs estimate, a wave state–dependent bias is also identified, with steep (smooth) waves producing a negative (positive) bias relative to buoys. A systematic difference in the Hs being reported by MEDS and NDBC buoy networks is also noted. Using the altimeter data as a common reference, it is estimated that MEDS buoys are underestimating Hs relative to NDBC buoys by about 10%.
- Subjects
REMOTE sensing equipment; ARTIFICIAL satellite equipment; ALTIMETERS; ALTITUDES; THEORY of wave motion; BUOYS; SYSTEM analysis; DATA analysis
- Publication
Journal of Atmospheric & Oceanic Technology, 2009, Vol 26, Issue 1, p123
- ISSN
0739-0572
- Publication type
Article
- DOI
10.1175/2008JTECHO598.1