The TOPEX/POSEIDON Geophysical Data Record (GDR) contains global coverage altimeter data. The objective of the TOPEX/POSEIDON mission, launched in August 1992, is to determine ocean topography with a sea surface height measurement precision of 3 cm and a sealevel measurement accuracy of 13 cm. The dataset contains measurements from two altimeters, a NASA dual frequency (Ku and C band) instrument similar to the Geosat altimeter, and a French space agency (CNES) instrument which is a proof-of-concept solid-state altimeter (Ku band). It also contains Sea Surface Height (SSH), significant wave height, ionospheric correction, tides and other geophysical corrections. It is emphasized that this product is considered research data because of the form and content of the data. The data consist entirely of files comprising headers and data records which contain over a hundred parameters for each second. It is swath data and there are no images. Analysis software is the responsibility of the user. Calculation of sea surface height anomalies from the altimeter range and environmental corrections is the responsibility of the user. The data are arranged in 10 day cycles that are separated into 254 passes, each about 56 minutes.

The Integrated Multi-Mission Ocean Altimeter Sea Surface Height (SSH) Version 5.2 dataset provides level 2 along track sea surface height anomalies (SSHA) for 10-day cycles from the TOPEX/Poseidon, Jason-1, OSTM/Jason-2, Jason-3, and Sentinel-6A missions geo-referenced to a mean reference orbit. It is produced by NASA Sea Surface Height (NASA-SSH) project investigators at Goddard Space Flight Center and Jet Propulsion Laboratory with support from NASA’s Physical Oceanography program, and was developed originally as an Earth System Data Record (ESDR) under the Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, which supported forward processing and incremental refinements through version 5.1 (released in April 2022). Geophysical Data Records (GDRs) from each altimetry mission were interpolated to a common reference orbit with biases and cross-calibrations applied so that the derived SSHA are consistent between satellites to form a single homogeneous climate data record. The entire multi-mission data record covers the period from September 1992 to present; it is extended to include new observations approximately once each quarter. The previous release (version 5.1) integrated Jason-3 data and applied revised internal tides and pole tide across missions (GDR_F standard). The current release (version 5.2) includes the following revisions: a) GSFC std2006_cs21 orbit for all missions, b) GOT5.1 ocean tide model, c) TOPEX/Poseidon GDR_F data, d) Sentinel-6 LR version F08 data, e) Jason-3 re-calibrated radiometer wet troposphere correction. More information about the data content and derivation can be found in the v5.2 User’s Handbook (https://doi.org/10.5067/ALTUG-TJ152). Please note that this collection contains the same data as https://doi.org/10.5067/ALTTS-TJA52, re-organized into one netCDF file per cycle for convenience.

Provides L2P high resolution (HR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft, and contains L2-equivalent geophysical sea-state data at a slightly different latency than the other L2 NRT products. The sea-state data were derived from L1B altimetry, and include range, orbital altitude, time, and water vapour. Environmental and geophysical corrections, significant wave height, and wind-speed information are supplied by the AMR-C. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L1B high resolution (HR) non-time critical (NTC; 60-day latency) altimetry data from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft which include the geolocated, fully SAR processed and calibrated multi-looked HR Ku-band waveforms. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides L2P low resolution (LR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft, and contains L2-equivalent geophysical sea-state data at a slightly different latency than the other L2 NRT products. The sea-state data were derived from L1B altimetry, and include range, orbital altitude, time, and water vapour. Environmental and geophysical corrections, significant wave height, and wind-speed information are supplied by the AMR-C. The S6A NTC product is analogous to the Jason-3 GDR product.

Provides reprocessed L2 high resolution (HR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft. It contains Sea Surface Height (SSH), Sea Surface Height Anomalies (SSHA) and Significant Wave Height (SWH), along with 1 Hz and 20 Hz Ku-band measurements processed from L1B altimetry including the range, orbital altitude, time, and water vapour. It also includes altimetry corrections, significant wave height and wind-speed from the AMR-C. This standard product release provides the geophysical parameters at both 1 and 20 Hz. The S6A NTC product is analogous to the Jason-3 GDR product.

This data set contains time series moored buoy data collected in the Bering Sea by Pacific Marine Environmental Laboratory (PMEL) during the period of September 8, 1975 to July 28, 1982. The data consists of pressure and temperature readings. The original tape was in ASCII format and is currently available in the NODC format. These data were collected as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) project conducted by National Oceanic and Atmospheric Administration (NOAA). Principal Investigator for this study was Dr. James D. Schumacher.

Current speed/direction, depth and other data were collected using meteorological sensors, Secchi disk, buoy, and bottle casts casts from multiple ships from December 6, 1975 to September 30, 1978. Data were submitted by USSR Academy of Science; Institute of Oceanology as part of the IDOE/POLYMODE (International Decade of Ocean Exploration / combination of USSR POLYGON project).

Provides L2 high resolution (HR) non-time critical (NTC; 60-day latency) altimetry from the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft. It contains Sea Surface Height (SSH), Sea Surface Height Anomalies (SSHA) and Significant Wave Height (SWH), along with 1 Hz and 20 Hz Ku-band measurements processed from L1B altimetry including the range, orbital altitude, time, and water vapour. It also includes altimetry corrections, significant wave height and wind-speed from the AMR-C. This standard product release provides the geophysical parameters at both 1 and 20 Hz. The S6A NTC product is analogous to the Jason-3 GDR product.