Jason-3 altimeter data is part of the Copernicus programme and is used by the Copernicus Marine Environment Monitoring Service (CMEMS).

As the altimetry reference mission, Jason-3 links up the other altimeter missions — Sentinel-3, Altika, Cryosat-2 and HY-2A — by precisely determining any bias between them and by adjusting them against the Jason-3 reference mission.


Why the Jason-3 mission?


1. Measurements of ocean topography — the equivalent of surface pressure in the atmosphere — enabling numerical prediction of the three-dimensional ocean, a prerequisite to the development of operational oceanography, in combination with marine meteorology.
2. Helping improve monthly forecasts, e.g. heatwaves or sustained heavy rainfall, and seasonal forecasts, e.g. a cold winter or a hot summer, due to the sustained influence of the ocean on the atmosphere.
3. Variations of sea level (some mm per year) in our changing climate can only be monitored on global scale by High Precision Ocean Altimetry (HPOA) observations (composed of Jason-3 and future Jason-CS data), and ocean surface topography measurements are essential to understand how the ocean stores and redistributes heat, water and carbon in the climate system.
4. Altimeter observations are a unique source of ocean surface wind speed measurements for the validation of the new very high resolution (1 to 2 km) regional Numerical Weather Prediction models, to improve short range prediction of high impact weather, such as hurricanes.

Providing vital ocean data


Jason-3 provides data on the decadal (10-yearly) oscillations in large ocean basins, such as the Atlantic Ocean; mesoscale variability, and surface wind and wave conditions. This data is vital to our understanding of weather forecasting and climate change monitoring. Jason-3 measurements contribute to the European Centre for Medium-Range Weather Forecasts (ECMWF) satellite data assimilation, helping improve global atmosphere and ocean forecasting.

Altimetry data from Jason-3 helps in the creation of detailed decade-long global observations and analyses of the El Niño and La Niña phenomena, providing insights int ocean circulation and its effects on climate; ocean tides; turbulent ocean eddies, and marine gravity.

Mission applications

Short-range ocean forecasts

Short range ocean forecasts are useful in a variety of applications:

  • Sustainable management of ocean resources.
  • Monitoring of fishing vessel and merchant shipping fleets.
  • Safety of people and property at sea.
  • Environmental protection.
  • Harbour management.
  • Sizing of port and maritime structures.
  • Management and monitoring of coastal resources and environments.
  • Tourism.

Seasonal forecasting and climate monitoring

Seasonal forecasting aims to provide useful information about the climate that can be expected in the coming months. Having a precise knowledge of the ocean state is essential when trying to forecast what the climate will be like six months ahead, thus altimetrsource of vital data for seasonal forecasting models. Altimetry factsheet (PDF, 147 KB)

Changes in the energy balance between the oceans and atmosphere play an important role in the planet's climate change. From the seasonal to the decadal, or even the centennial timeframe, knowledge about the ocean state and its influence upon the atmosphere is one of the keys to climate forecasting. Jason-3 aids a better understanding of how oceans and climate interact.

How does it work?


The Jason missions use radar altimetry sensors that measure the time a signal takes to bounce off the ocean surface and return to the satellite, to provide global measurements of sea surface height that are accurate to within a few centimetres. This information, combined with GPS and DORIS measurements of the satellite's location, allows complete global mapping of sea surface height once every 10 days. Jason-3 follows the same design as Jason-2. It is based on the same Proteus platform delivered by CNES and has the same US and European instruments.

Jason-3 design

What data is available?


A full suite of Jason-3 products are available include\ing significant wave height, wind speed and sea surface height.

  • Geophysical Data Record (GDR) — available within 60 days.
  • Near-real time (NRT) Operational Geophysical Data Records (OGDR) — available within three hours
  • Non-time critical (NTC) Interim Geophysical Data Record (IGDR) — available within two days
Jason-3 products
Name Instrument Data Access
Interim Geophysical Data Record - Jason-3 POSEIDON-3B Download,
Interim Geophysical Data Record - Sea Surface Height - Jason-3 POSEIDON-3B Download,
Operational Geophysical Data Record (BUFR) - Jason-3 POSEIDON-3B EUMETCast-Europe,
EUMETSAT Data Centre,
Operational Geophysical Data Record (netCDF) - Jason-3 POSEIDON-3B EUMETCast-Africa,
EUMETSAT Data Centre
Operational Geophysical Data Record - Sea Surface Height Anomaly - Jason-3 POSEIDON-3B EUMETCast-Africa,
EUMETSAT Data Centre

How do I get the data?

Users need to be registered to get access to the Jason-3 products. To do this you need to use our Earth Observation Portal (EOP). To access the Earth Observation Portal (EOP) for the first time, users need to create an account. Once the account has been created, you can log in to view and modify your profile, service subscriptions and licence arrangements.

Jason-3 products are available:

Access to the products is governed by appropriate user subscriptions at the time of registration.

Jason-3 documentation

Title Type Reference Ver
Jason-3 Products Handbook PG SALP-MU-M-OP-16118-CN 1A

Mission Facts

  • Launched: 17 January 2016, Vandenberg Air Force Base in California, on a SpaceX Falcon 9 launcher.
  • Operational:14 October 2016.
  • Orbit: Non-sun-synchronous low Earth orbit at 66° inclination and 1336 km altitude, optimised to eliminate tidal aliasing from sea surface height and mean sea level measurements. Jason-2, flies on the same orbit but at 162°
  • Built on the same cooperation as Jason-2, involving EUMETSAT, NOAA, CNES and NASA, with Copernicus expected to support the European contribution to operations, as part of its HPOA activity, which also covers contributions to the Jason-CS programme.

Jason-3 videos

Videos the applications of Jason-3 satellite data.

  • Coasts
    CNES video, outlining how Jason satellite data is used to monitor coastal erosion and predict flooding.
  • Marine Wildlife
    CNES video, illustrating how Jason data is used to track and assist in the protection of marine wildlife.
  • Sea Level
    CNES video, outlining how Jason satellite data is used to monitor global sea levels.
  • The Water Cycle
    CNES video, illustrating how Jason data is helping us understand the water cycle.
  • Operational Oceanography
    CNES video, outlining how Jason satellite data is helping support operational oceanography around the globe.
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