Abstract
We present a 17-year calibration record of precise (Jason-class) spaceborne altimetry from a California offshore oil platform (Harvest). Our analyses indicate that the sea-surface-height (SSH) biases for all three TOPEX/Poseidon (1992–2005) measurement systems are statistically indistinguishable from zero at the 15 mm level. In contrast, the SSH bias estimates for the newer Jason-1 mission (2001–present) and the Ocean Surface Topography Mission (2008–present) are significantly positive. In orbit for over eight years, the Jason-1 measurement system yields SSH biased by +94 ± 15 mm. Its successor, OSTM/Jason-2, produces SSH measurements biased by +178 ± 16 mm.
Acknowledgments
We are indebted to Plains Exploration and Production for hosting our experiment on platform Harvest, and supporting our trips to the platform. We dedicate our efforts to Edward “Chris” Christensen and Yves Menard. Their shared vision, leadership, and advocacy of the cal/val program are responsible for the fact that Harvest continues to return useful scientific data 17 years beyond the end of the T/P verification phase for which it was designed. The Harvest experiment is a multiagency effort, and we are indebted to numerous individuals for engaging in the design, installation, operation, and maintenance of the sensors, as well as interpretation of the data. They include Dan Kubitschek, Dave Stowers, Kevin Miller, Steve Dinardo, and Charles Morris (JPL); Razmik Khachikyan (Raytheon); Chuck Fowler and Scott Washburn (CU); Steve Gill, Mickey Moss, Eddie Shih, Jim Russell, Clyde Kakazu, and Mark Bailey (NOAA); and K. C. Rockwell (PXP). The Harvest research activities are funded by the NASA Physical Oceanography Program. We are grateful to Eric Lindstrom and Lee Fu for advancing the Harvest experiment and for assisting with the renewal of interagency agreements needed for experiment upgrades. A portion of the work described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.