CoAuthors

Adam Dodge (University of Colorado, United States); Bruce Haines (NASA/JPL, United States); Robert Leben (University of Colorado, United States); R. Steven Nerem (University of Colorado, United States)

Since the TOPEX-Poseidon mission, the University of Colorado and JPL have operated a lidar laser ranging instrument on the Harvest Platform in support of altimeter calibration and validation. The instrument is a small, COTS device that continuously estimates the vertical range to the sea surface from a lower deck of the oil platform. The lidar collects measurements coincident with the reference altimeter and in concert with a suite of other tide gauge instruments mounted on the Harvest Platform: two nitrogen bubblers and two radar ranging units operated by NOAA. Although the nitrogen bubbler systems are used as the main reference for altimetry cal/val studies at the Harvest Platform [Haines et al, 2016], the lidar has provided redundancy and insight into effects of sea state on the in situ sea level measurements [Washburn et al., 2011]. Past work has shown that the in situ measurements are sensitive to the sea state conditions and experience effects similar to the satellite radar altimeter sea state bias (SSB) correction. Therefore, the lidar measurements or other future measurements of sea state at Harvest Platform may yield insight into improving the SSB correction. Here we report on recent lidar data collected at the Harvest Platform and an analysis of these data for sea level estimates and their sensitivity to sea state conditions. We also report on a new deployment of the lidar instrument at the USC Wrigley Marine Science Center near Two Harbors, CA on the island of Catalina. This new lidar deployment at Two Harbors is on a Jason-3 ascending track and is an experiment to determine the feasibility of future altimeter cal/val studies in the San Pedro Channel between Catalina and Los Angeles, CA.

References
Haines, B., Desai, S., Shah, R., Leben, R., Masters, D., Nerem, R. S., … Stalin, S. (2016). The Harvest Experiment: Connecting Jason-3 to the Long-Term Sea Level Record. Presented at the OSTST 2016, La Rochelle, France.

Washburn, S. A., Haines, B. J., Born, G. H., & Fowler, C. (2011). The Harvest Experiment LIDAR System: Water Level Measurement Device Comparison for Jason-1 and Jason-2/OSTM Calibration. Marine Geodesy, 34(3-4), 277–290. https://doi.org/10.1080/01490419.2011.590114