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Ocean Surface Topography from Space
MISSIONS

Mission Basics

Jason-3 Anticipated Launch: 2015

OSTM/Jason-2
Launched: June 20, 2008

OSTM/Jason-2 - The Ocean Surface Topography Mission on the Jason-2 satellite, is a follow-on to Jason-1. It takes oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications.

Jason-1
Launched: December 7, 2001, Decommissioned: July 2013.

Jason-1 continued the task of providing the important oceanographic data time-series originated by TOPEX/Poseidon, carrying updated versions of the same instruments. It flew in tandem with TOPEX/Poseidon for 5 years. (See the Tandem Mission Flash animation for more details).

TOPEX/Poseidon
Launched: August 10, 1992, Decommissioned: January 2006.

TOPEX/Poseidon data has revolutionized the way the global ocean is studied. For the first time, the seasonal cycle and other temporal variabilities of the ocean were determined globally with high accuracy, yielding fundamentally important information for testing ocean circulation models. Major observations were made using TOPEX/Poseidon data on

  • Oceanic circulation including details on the movement of Rossby and Kelvin waves
  • Oceanic and coastal tides
  • El Niño, La Niña, and the Pacific Decadal Oscillation
  • El Niño-like circulation in the Atlantic Ocean
  • Oceanic seasons in the Mediterranean
  • Ocean floor topography from surface data used to refine the geoid model


GRACE
Launched: March 17, 2002

GRACE - Gravity Recovery and Climate Experiment, is flying two identical spacecraft about 220 kilometers apart in a 500-kilometer elevation polar orbit producing monthly maps of the geoid. The geoid is a hypothetical surface of the Earth that is coincident with mean sea level. It is perpendicular, at every point, to Earth’s gravity. It is the basic surface on which all altimetry data is based.

SWOT
Anticipated Launched: 2020



Mission Details

TOPEX/Poseidon launch image
TOPEX/Poseidon Launch
The agreement in 1987 between CNES and NASA to join resources and expertise on the TOPEX/Poseidon project culminated 20 years of development into using a spaceborne radar altimeter to measure ocean-surface topography.

TOPEX/Poseidon was launched August 10, 1992 from the ESA launch facility at Kourou, French Guiana, aboard an Ariane 42P launch vehicle. TOPEX/Poseidon data revolutionized the way the global ocean is studied. For the first time, the seasonal cycle and other temporal variabilities of the ocean were determined globally with high accuracy, yielding fundamentally important information for testing ocean circulation models. Many major observations were made using TOPEX/Poseidon data.

Recognizing the importance of continuing ocean surface topography measurement, NASA and CNES approved Jason-1 as a joint follow-on to TOPEX/Poseidon. Many years of scientific discovery by TOPEX/Poseidon have broadened its original list of science objectives.

Jason-1 launch
Jason-1 Launch
Jason-1 flew as a joint NASA/CNES follow-on to TOPEX/Poseidon. OSTM/Jason-2 is a joint NASA/CNES/NOAA/Eumetsat mission, launched as a follow-on to Jason-1. Each of the spacecraft carry 5 similar or identical instruments. On OSTM/Jason-2, the CNES-supplied spacecraft carries the payload of five instruments: the POSEIDON-3 dual frequency altimeter, the mission's main instrument which measures altitude; the Advanced Microwave Radiometer (AMR) to measure perturbations due to atmospheric water vapor; and the three location-finding systems: the DORIS Doppler orbitography beacon, the laser retroreflector array (LRA), and the Global Positioning System Payload (GPSP). These instruments are designed to provide measurements for at least 5 years. Jason-1 and OSTM/Jason-2 were launched from Vandenberg AFB aboard NASA-supplied Delta rockets, Jason-1 on December 7, 2001, and OSTM/Jason-2 on June 20, 2008.

After TOPEX/Poseidon was decommissioned in January 2006, for the next 11-1/2 years, Jason-1 continued the task of providing the important oceanographic data time-series originated by its predecessor. Jason-1 was decommissioned in July 2013, and now OSTM/Jason-2 continues this important data into the third decade.

OSTM/Jason-2 is integrated into numerous international climate-study programs, provides near real-time data access, and marks the beginning of the operational era of collecting these critical oceanographic parameters. The next in the altimeter series, Jason-3, is planned for launch in 2015.



Where are they now?

Where is it now - screen shot
Where are they now?
Have you ever looked up in the night sky to see a satellite? Have you wondered what satellite it was? Maybe it was OSTM/Jason-2. You can find out! See where OSTM/Jason-2 is right now.

To find out when you can view this satellite from your area, go to Heavens-Above and follow the directions below.

  1. Under Configuration, and “Current observing site”, select your location from their map or database. If you want to enter your coordinates manually, follow the instructions on the link, “edit manually”.
  2. Read the instructions and enter your town or village.
  3. If a list of towns are returned, select the correct one.
  4. Under Satellites, choose "Select a satellite from the database."
  5. In the Satellite Name: field enter jason for the Jason-1 satellite, or jason 2 (no dash) for OSTM/Jason-2.
  6. From the Satellite Search Results list, select the satellite.
  7. In the upper right of the page, select Passes to see when you can view the satellite from your location.

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