Progress on Retracked TOPEX Data for the Climate Data Record

Philip Callahan (Jet Propulsion Laboratory, United States)


Shailen Desai (Jet Propulsion Laboratory, United States); Nicolas Picot (CNES, France); Jean-Damien Desjonqueres (Jet Propulsion Laboratory, United States); Joshua Willis (Jet Propulsion Laboratory, United States); Thierry Guinle (CNES, France)

Event: 2017 Ocean Surface Topography Science Team Meeting

Session: Instrument Processing: Measurement and Retracking

Presentation type: Type Oral

We will report progress on delivering the TOPEX Climate Data Record product. The main efforts for this product are retracking the data to account for waveform leakages and point target response (PTR) changes and updating other components of the record and format to be compatible with Jason GDRs.

Previous reports on this work included:
(1) Determining that leakages limited the use of the Cal-1 data for generating PTRs to the first seven lobes.
(2) Developing methods to extend the PTR to the necessary 30 lobes to reach full accuracy.
(3) Determining that it was not feasible to improve upon the original WFF waveform weights.
(4) Determining that WFF range calibration correction derived from specialized processing of internal calibration data is largely accounted for when the Cal-1 PTRs and earlier noise gates are used in retracking.

The final climate product will include a format as closely aligned with Jason Ver E as possible. CNES is supplying auxiliary geophysical corrections, fields, and orbits updated to the Jason Ver E standards. With these enhancements, a final sea state bias correction will be determined.

To validate the version of retracking incorporating the features listed above, the newest data have been compared to Jason-1 during the TOPEX/Jason-1 colinear phase. Other validation will include: comparison to global geophysical data; comparison with the global set of tide gauges analyzed by the Ray-Beckley group; and waveform simulations with varying PTRs. Details of the retracking and validation work to date will be presented.

(Much of the work reported here is based on work by Joseph McMichael (1) when he was at JPL.)

The work reported here was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Copyright 2017.

Oral presentation show times:

RoomStart DateEnd Date
Symphony Ballroom IV Tue, Oct 24 2017,09:00 Tue, Oct 24 2017,09:15
Philip Callahan
Jet Propulsion Laboratory
United States