---
aliases:
  - context: instrumentID
    lexicon: ceos
    term: 765
    url: http://database.eohandbook.com/database/instrumentsummary.aspx?instrumentID=765
  - context: Instrument
    lexicon: ceos
    term: TOPEX
    url: http://database.eohandbook.com/database/instrumentindex.aspx#T
  - context: Sensor
    lexicon: podaac
    term: TOPEX ALTIMETER
    url: ~
cited_by: []
contributors:
  - display_name: 'Engineer : Johns Hopkins University Applied Physics Laboratory '
    href: http://52.38.26.42:8080/contributor/3698.yaml
    id: 3698
    organization:
      country_code: US
      display_name: Johns Hopkins University Applied Physics Laboratory
      identifier: johns-hopkins-university-applied-physics-laboratory
      name: Johns Hopkins University Applied Physics Laboratory
      organization_type_identifier: research
      type: organization
      url: http://www.jhuapl.edu/
    organization_uri: /organization/johns-hopkins-university-applied-physics-laboratory
    person: {}
    person_id: ~
    person_uri: ~
    role_type_identifier: engineer
    uri: /contributor/3698
  - display_name: 'Manager : NASA Goddard Space Flight Center '
    href: http://52.38.26.42:8080/contributor/3699.yaml
    id: 3699
    organization:
      country_code: US
      display_name: NASA Goddard Space Flight Center
      identifier: goddard-space-flight-center
      name: NASA Goddard Space Flight Center
      organization_type_identifier: federal
      type: organization
      url: http://www.nasa.gov/centers/goddard
    organization_uri: /organization/goddard-space-flight-center
    person: {}
    person_id: ~
    person_uri: ~
    role_type_identifier: manager
    uri: /contributor/3699
  - display_name: 'Contributor : National Aeronautics and Space Administration '
    href: http://52.38.26.42:8080/contributor/3713.yaml
    id: 3713
    organization:
      country_code: US
      display_name: National Aeronautics and Space Administration
      identifier: national-aeronautics-space-administration
      name: National Aeronautics and Space Administration
      organization_type_identifier: federal
      type: organization
      url: http://www.nasa.gov
    organization_uri: /organization/national-aeronautics-space-administration
    person: {}
    person_id: ~
    person_uri: ~
    role_type_identifier: contributor
    uri: /contributor/3713
description: "The dual-frequency NASA radar altimeter, NRA, was the primary instrument aboard the spacecraft. It worked by sending radio pulses at 13.6 GHz and 5.3 GHz toward the earth and measuring the characteristics of the echo. By combining this measurement with data from the microwave radiometer and with other information from the spacecraft and the ground, scientists were able to calculate the height of the sea surface to within 4.3 centimeters.\n"
description_attribution: "https://sealevel.jpl.nasa.gov/technology/technologyinstrumentdescription/instrumentdescriptaltimeter/\n"
display_name: topex-nasa-radar-altimeter
files:
  - display_name: tp-altimeter-th2.gif
    file: 3a/3b/6f97ec848e6c9a0cc82cc26431d3/tp-altimeter-th2.gif
    href: http://data.globalchange.gov/assets/3a/3b/6f97ec848e6c9a0cc82cc26431d3/tp-altimeter-th2.gif
    identifier: b5350058-03ba-49a8-a47f-139990a238ef
    landing_page: https://sealevel.jpl.nasa.gov/technology/technologyinstrumentdescription/instrumentdescriptaltimeter/
    location: ~
    mime_type: image/gif
    sha1: 06395c8bad023f437352891c4702767f1ce8ffac
    size: 8025
    thumbnail: 3a/3b/6f97ec848e6c9a0cc82cc26431d3/.thumb-b5350058-03ba-49a8-a47f-139990a238ef.png
    thumbnail_href: http://data.globalchange.gov/assets/3a/3b/6f97ec848e6c9a0cc82cc26431d3/.thumb-b5350058-03ba-49a8-a47f-139990a238ef.png
    type: file
    uri: /file/b5350058-03ba-49a8-a47f-139990a238ef
    url: http://data.globalchange.gov/assets/3a/3b/6f97ec848e6c9a0cc82cc26431d3/tp-altimeter-th2.gif
href: http://52.38.26.42:8080/instrument/topex-nasa-radar-altimeter.yaml
identifier: topex-nasa-radar-altimeter
name: TOPEX NASA Radar Altimeter
parents: []
platforms:
  - description: "TOPEX/Poseidon (or simply T/P) is a cooperative Earth observation mission of the USA and France (NASA/JPL and CNES as partners) with the overall objective to provide high-accuracy global sea level (ocean height) measurements in coordinates relative to the center of the Earth. From this information, ocean circulation patterns can be mapped. The T/P data analysis helps to understand how the oceans interact with the atmosphere, and improve our ability to predict the global climate. NASA provided the satellite bus, five instruments, and is responsible for spacecraft operations. CNES furnished two of the spacecraft's instruments and the mission's Ariane launch vehicle."
    description_attribution: "TOPEX/Poseidon (or simply T/P) is a cooperative Earth observation mission of the USA and France (NASA/JPL and CNES as partners) with the overall objective to provide high-accuracy global sea level (ocean height) measurements in coordinates relative to the center of the Earth. From this information, ocean circulation patterns can be mapped. The T/P data analysis helps to understand how the oceans interact with the atmosphere, and improve our ability to predict the global climate. NASA provided the satellite bus, five instruments, and is responsible for spacecraft operations. CNES furnished two of the spacecraft's instruments and the mission's Ariane launch vehicle."
    identifier: topex-poseidon
    name: Topographic Experiment/Poseidon
    uri: /platform/topex-poseidon
references: []
type: instrument
uri: /instrument/topex-nasa-radar-altimeter