Data Records derived from GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) data from 30 March 1985 to 31 December 1989

browse graphicPreview graphic
This collection contains Sensor Data Records (SDRs), Geodetic Data Records (GDRs), Waveform Data Records (WDRs), and Crossover Difference data Records (XDRs) from the GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) for the time period of March 30, 1985 to December 31, 1989. Parameters include: time, orbit, latitude/longitude, and sea surface height. Corrections to the data include: sea level, wind and wave data, tides, dry and wet troposphere, ionosphere, height bias, altimeter crossover differences, altimeter sea surface measurement, and spacecraft orientation. These data were submitted by the U.S. Navy via National Ocean Service.

This collection also contains complete copies of four NODC Standard Products, including US Navy Geosat altimeter geophysical data records (GDRs) for the Geodetic Mission (4 CD-ROMs), US Navy Geosat wind/wave data (WWDR) from the Geodetic Mission (4 CD-ROMs), US Navy Geosat Enhanced JGM-3 Geophysical Data Records (GDR) from the Geodetic and Exact Repeat Missions (4 CD-ROMs), and US Navy Geosat altimeter Crossover Differences (XDRs) for the Geodetic Mission (8 CD-ROMs).

The US Navy Geosat (Geodetic Satellite) radar altimeter mission lasted for nearly 5 years (March 1985 to January 1990) and collected approximately 750 million measurements of sea level, wave height, and wind speed over the global oceans. During the Geodetic Mission (March 1985 to September 1986), the satellite did not repeat its ground track for the duration of the mission. The orbit of the satellite was changed in early October 1986 to begin the Exact Repeat Mission (ERM) which lasted from November 8, 1986 until the satellite quit functioning in January 1990. During the ERM, the satellite repeated its ground track every 17 days. Data were initially processed by the Johns Hopkins University Applied Physics Laboratory in Laurel, MD in coordination with the NOAA/NOS Satellite Altimeter Group. Data products were transferred to the NOAA National Oceanographic Data Center (NODC) for distribution. Data products are archived at the NODC.

From March 1985 until January 1990, the U.S. Navy satellite Geosat generated a new data set with unprecedented spatial and temporal coverage of the global oceans. Designed and built at the Johns Hopkins University Applied Physics Laboratory, Geosat carried a radar altimeter which produced profiles of sea level, wave height, and wind speed along the satellite ground track. Such records have applications in many areas of geodesy, ocean dynamics, and global climate research. Experience with GEOS-3 and Seasat in the 1970s had demonstrated the enormous potential of altimetry, but neither mission provided such complete long-term global coverage.

Geosat was launched on March 12, 1985, and altimeter data collection began on March 30. The acronym Geosat was derived from geodetic satellite, because its primary mission was to obtain a high-resolution description of the marine geoid up to latitudes of 72 degrees. This goal was achieved during the first 18 months, known as the Geodetic Mission (GM). During this time the ground track had a near-repeat period of about 23 days (330 revolutions in 23.07 days; average orbital period of 6039.84 sec). The drifting orbit resulted in a dense, global network of sea level profiles separated by about 4 km at the equator. Because of the military significance of this unique set of observations, the GM data were initially classified but in 1995 were released to NOAA in their entirety for public distribution.

At the conclusion of the GM on September 30, 1986, the satellite orbit was changed, and the Exact Repeat Mission (ERM) began on November 8, 1986. This produced sea level profiles along tracks that repeated themselves within 1-2 km at intervals of about 17 days (244 revolutions in 17.05 days; average orbital period of 6037.55 sec). The ERM covered 62 complete 17-day cycles before tape recorder failure in October 1989 terminated the global data set. A limited amount of data was subsequently collected by direct broadcast in the North Atlantic and Gulf of Mexico. By January 1990 continued degradation of the altimeter output power finally ended the Geosat mission.
  • Cite as: Lillibridge, John; Cheney, Robert; Doyle, Nancy; US DOC/NOAA/NESDIS > Center for Satellite Applications and Research; US DOC/NOAA > National Ocean Service; US DOC/NOAA > NOS - Rockville, MD; US Navy > Naval Oceanographic Office; US Navy > Office of Naval Research (1987). Data Records derived from GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) data from 30 March 1985 to 31 December 1989. National Oceanographic Data Center, NOAA. Dataset. [access date]
gov.noaa.nodc:GEOSAT-GM-ERM
Search Data
  • Granule Search (search)
    Search for data granules belonging to this collection (a granule is the smallest aggregation of data that can be independently described and retrieved).
Distribution Formats
  • Originator data format
Ordering Instructions Data may be searched and downloaded using online services provided by NCEI using the online resource URLs in this record. Contact NCEI Information Services for custom orders. When requesting data from NCEI, the desired data set may be referred to by the unique package identification number listed in this metadata record.
Distributor DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
301-713-3277
NCEI.Info@noaa.gov
Dataset Point of Contact Information Services
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
301-713-3277
NCEI.Info@noaa.gov
Time Period 1985-03-31 to 1989-12-31
Spatial Bounding Box Coordinates
N: 90
S: -90
E: 180
W: -180
Spatial Coverage Map
General Documentation
Associated Resources
  • Documentation for Geosat Geodetic Mission Sensor Data Records (SDR) and Waveform Data Records (WDR) archived at NODC (NODC Accession 0002202)
Publication Dates
  • publication: 1987-02-26
  • revision: 2017-01-29
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Data Update Frequency As needed
Supplemental Information
Documentation for GEOSAT data accessions is maintained in NODC Accession 0002202 (https://accession.nodc.noaa.gov/0002202).

Note: Metadata for some accessions in this collection were extracted from a legacy database maintained by the U.S. National Oceanographic Data Center (NODC). The design of the database did not exactly reflect the FGDC Content Standard for Digital Geospatial Metadata (CSDGM).

Principal Investigator (PI) and organization contact information accurately represents all available information from the legacy database at the time that this description was created. However, proper attribution of a PI to a specific institution or the role (submitting or collecting) taken by an institution may not be correct due to inexact mapping between fields in the legacy database and the CSDGM. Due to this uncertainty, the contact information was initially recorded in the Supplemental Information element of the CSDGM description.

To develop more accurate metadata, the NODC reviews metadata for all accessions on an ongoing basis.
Purpose Basic research
Use Limitations
  • accessLevel: Public
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Dataset Citation
  • Cite as: Lillibridge, John; Cheney, Robert; Doyle, Nancy; US DOC/NOAA/NESDIS > Center for Satellite Applications and Research; US DOC/NOAA > National Ocean Service; US DOC/NOAA > NOS - Rockville, MD; US Navy > Naval Oceanographic Office; US Navy > Office of Naval Research (1987). Data Records derived from GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) data from 30 March 1985 to 31 December 1989. National Oceanographic Data Center, NOAA. Dataset. [access date]
Cited Authors
Contributors
Resource Providers
Publishers
Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • oceanography
Global Change Master Directory (GCMD) Science Keywords
  • EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > AIR TEMPERATURE
  • EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS > WIND DIRECTION
  • EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS > WIND SPEED
  • EARTH SCIENCE > OCEANS > OCEAN WAVES
  • EARTH SCIENCE > OCEANS > OCEAN WAVES > SEA STATE
  • EARTH SCIENCE > OCEANS > OCEAN WAVES > WAVE HEIGHT
  • EARTH SCIENCE > OCEANS > OCEAN WAVES > WAVE SPEED/DIRECTION
  • EARTH SCIENCE > OCEANS > SEA SURFACE TOPOGRAPHY
  • EARTH SCIENCE > OCEANS > TIDES
  • EARTH SCIENCE > OCEANS > TIDES > TIDAL HEIGHT
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NODC > National Oceanographic Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/STAR > Center for Satellite Applications and Research, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NMFS > National Marine Fisheries Service, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NOS > National Ocean Service, NOAA, U.S. Department of Commerce
NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS
Platform keywords NODC PLATFORM NAMES THESAURUS Global Change Master Directory (GCMD) Platform Keywords
  • GEOSAT > Geodetic Satellite
Instrument keywords NODC INSTRUMENT TYPES THESAURUS
Place keywords NODC SEA AREA NAMES THESAURUS Global Change Master Directory (GCMD) Location Keywords
  • GEOGRAPHIC REGION > GLOBAL OCEAN
  • OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN
  • OCEAN > INDIAN OCEAN
  • OCEAN > PACIFIC OCEAN > SOUTH PACIFIC OCEAN
  • OCEAN > SOUTHERN OCEAN
Keywords NCEI ACCESSION NUMBER
Use Constraints
  • Cite as: Lillibridge, John; Cheney, Robert; Doyle, Nancy; US DOC/NOAA/NESDIS > Center for Satellite Applications and Research; US DOC/NOAA > National Ocean Service; US DOC/NOAA > NOS - Rockville, MD; US Navy > Naval Oceanographic Office; US Navy > Office of Naval Research (1987). Data Records derived from GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) data from 30 March 1985 to 31 December 1989. National Oceanographic Data Center, NOAA. Dataset. [access date]
Access Constraints
  • NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Fees
  • Digital data may be downloaded from NCEI at no charge in most cases. For custom orders of digital data or to obtain a copy of analog materials, please contact NCEI Information Services for information about current fees.
Lineage information for: series
Processing Steps
  • 2010-12-18T15:25:11 - NCEI Accession 8800124 v1.1 was published.
  • 2010-12-18T16:59:06 - NCEI Accession 9300006 v1.1 was published.
  • 2011-01-14T18:18:54 - NCEI Accession 0053056 v1.1 was published.
  • 2011-01-14T18:19:46 - NCEI Accession 0053521 v1.1 was published.
  • 2011-01-14T18:20:18 - NCEI Accession 0053782 v1.1 was published.
  • 2011-01-14T18:20:32 - NCEI Accession 0054150 v1.1 was published.
  • 2011-01-14T18:21:35 - NCEI Accession 0054498 v1.1 was published.
  • 2011-01-16T18:11:56 - NCEI Accession 0054289 v1.1 was published.
  • 2011-01-16T22:51:52 - NCEI Accession 0061150 v1.1 was published.
  • 2011-01-25T04:59:00 - NCEI Accession 0002202 v1.1 was published.
  • 2011-01-25T04:59:18 - NCEI Accession 0002349 v1.1 was published.
  • 2011-01-25T04:59:31 - NCEI Accession 0002350 v1.1 was published.
  • 2011-01-25T04:59:45 - NCEI Accession 0002351 v1.1 was published.
  • 2011-01-25T04:59:58 - NCEI Accession 0002359 v1.1 was published.
  • 2011-01-25T05:00:04 - NCEI Accession 0002363 v1.1 was published.
  • 2011-01-25T05:00:32 - NCEI Accession 0002364 v1.1 was published.
  • 2011-01-25T05:01:02 - NCEI Accession 0002365 v1.1 was published.
  • 2011-01-25T05:01:23 - NCEI Accession 0002536 v1.1 was published.
  • 2011-01-25T05:01:37 - NCEI Accession 0002537 v1.1 was published.
  • 2011-01-25T05:01:50 - NCEI Accession 0002538 v1.1 was published.
  • 2011-01-25T05:02:04 - NCEI Accession 0002539 v1.1 was published.
  • 2011-01-25T05:02:19 - NCEI Accession 0002540 v1.1 was published.
  • 2011-01-25T05:02:33 - NCEI Accession 0002541 v1.1 was published.
  • 2011-01-25T05:02:46 - NCEI Accession 0002542 v1.1 was published.
  • 2011-01-25T05:02:59 - NCEI Accession 0002543 v1.1 was published.
  • 2011-01-25T05:03:12 - NCEI Accession 0002544 v1.1 was published.
  • 2011-01-25T05:03:26 - NCEI Accession 0002545 v1.1 was published.
  • 2011-01-25T05:03:39 - NCEI Accession 0002546 v1.1 was published.
  • 2011-01-25T05:03:52 - NCEI Accession 0002547 v1.1 was published.
  • 2011-01-25T05:04:06 - NCEI Accession 0002548 v1.1 was published.
  • 2011-01-25T05:04:19 - NCEI Accession 0002549 v1.1 was published.
  • 2011-01-25T05:04:33 - NCEI Accession 0002550 v1.1 was published.
  • 2011-01-25T05:05:02 - NCEI Accession 0002551 v1.1 was published.
  • 2011-01-25T05:05:32 - NCEI Accession 0002552 v1.1 was published.
  • 2011-01-25T05:06:01 - NCEI Accession 0002553 v1.1 was published.
  • 2011-01-25T05:06:29 - NCEI Accession 0002554 v1.1 was published.
  • 2011-01-25T05:06:59 - NCEI Accession 0002555 v1.1 was published.
  • 2011-01-25T05:07:29 - NCEI Accession 0002556 v1.1 was published.
  • 2011-01-25T05:07:58 - NCEI Accession 0002557 v1.1 was published.
  • 2011-01-25T05:08:29 - NCEI Accession 0002558 v1.1 was published.
  • 2011-01-25T05:08:57 - NCEI Accession 0002559 v1.1 was published.
  • 2011-01-25T05:09:27 - NCEI Accession 0002560 v1.1 was published.
  • 2011-01-25T05:09:55 - NCEI Accession 0002561 v1.1 was published.
  • 2011-01-25T05:10:25 - NCEI Accession 0002562 v1.1 was published.
  • 2011-01-25T05:10:54 - NCEI Accession 0002563 v1.1 was published.
  • 2011-01-25T05:11:23 - NCEI Accession 0002564 v1.1 was published.
  • 2011-01-25T05:11:52 - NCEI Accession 0002565 v1.1 was published.
  • 2011-01-25T05:12:21 - NCEI Accession 0002566 v1.1 was published.
  • 2011-04-22T14:05:39 - NCEI Accession 0053056 was revised and v2.2 was published.
Output Datasets
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Acquisition Information (collection)
Instrument
  • satellite sensor - altimeter
Platform
  • GEOSAT
Last Modified: 2018-11-27T20:41:41
For questions about the information on this page, please email: NODC.DataOfficer@noaa.gov