Friday, February 19, 2021

The PO.DAAC is pleased to announce the public release of the Integrated Multi-Mission Ocean Altimeter Sea Surface Height (SSH) Level 2 version 5.0 datasets, which are an extension of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Program. More information regarding the MEaSUREs mission and instrumentations is available from PO.DAAC’s mission webpage. These datasets provide a coherent and consistent time series of Sea Surface Height (SSH) from multi-mission altimeter data, including TOPEX/Poseidon, Jason-1, OSTM/Jason-2, and Jason-3 missions covering the period of September 1992 to October 2020. The development of the SSH Earth System Data Record (ESDR) was performed in part at NASA’s Goddard Space Flight Center, supported by NASA’s Physical Oceanography program. A portion of this work was carried out at the Jet Propulsion Laboratory.

Two datasets comprise this release: a single cycle SSH Level-2 version 5.0 (v5.0) and an integrated time series (all cycles) SSH Level-2 v5.0. The v5.0 data is updated from the previous v4.2 (DOI: and with extensive algorithm improvements and upgrades. The updates include improved Precise Orbit Determination (POD) with GSFC 2006 standards (std2006), the application of internal tides, and file metadata upgrades. More information on data processing methodology can be found in the v5.0 User Handbook. Both of the datasets are in netCDF-4 format. Single cycle SSH v5.0 consists of one cycle of SSH, which is approximately 10 days long, while the time series SSH v5.0 combines all cycles into one single file. As more recent SSH data is processed, data extensions are appended to the datasets on a quarterly interval. The Integrated Multi-Mission Ocean Altimeter SSH v5.0 datasets are described and discoverable via the PO.DAAC dataset information pages with following DOIs.




Beckley, B.; Zelensky, N.P.; Holmes, S.A.; Lemoine, F.G.; Ray, R.D.; Mitchum, G.T.; Desai, S.; Brown, S.T.. 2021. MERGED_TP_J1_OSTM_OST_ALL_V50. Ver. 5.0. PO.DAAC, CA, USA.

Beckley, B.; Zelensky, N.P.; Holmes, S.A.; Lemoine, F.G.; Ray, R.D.; Mitchum, G.T.; Desai, S.; Brown, S.T.. 2021. MERGED_TP_J1_OSTM_OST_CYCLES_V50. Ver. 5.0. PO.DAAC, CA, USA.


Beckley, et. al. 2017. On the “cal-mode” correction to TOPEX satellite altimetry and its effect on the global mean sea level time series. Journal of Geophysical Research: Oceans, 122. doi: 10.1002/2017JC013090

Lemoine, et. al. 2010, Towards development of a consistent orbit series for TOPEX, Jason-1, and Jason-2, Adv. Space Research, 46 (2010) 1513-1540, doi: 10.1016/j.asr.2010.05.007

Comments/Questions? Please contact or visit the PO.DAAC Ocean Topography Forum.