Editing Jason-1 (section)

== Satellite instruments ==
[[File:Jason1-altimeter-full.jpg|thumb|Poseidon radar altimeter]]
[[File:Jason1-lra-full.jpg|thumb|Laser retroreflector]]
[[File:Jason1-radiometer-full.jpg|thumb|[[Microwave]] Radiometer (JMR)]]
Jason-1 has five 5 instruments:
* Poseidon 2 – [[Nadir]] pointing [[Radar altimeter]] using [[C band (IEEE)|C band]] and {{Ku band}} for measuring height above [[sea]] surface.
* Jason [[Microwave]] [[Radiometer]] (JMR) –  measures [[water vapor]] along altimeter path to correct for pulse delay
* [[DORIS (geodesy)|DORIS]] ([[Doppler Effect|Doppler]] Orbitography  and Radiopositioning Integrated by [[Satellite]]) for orbit determination to within 10&nbsp;cm or less and [[ionosphere|ionospheric]] correction data for Poseidon 2.
* BlackJack [[Global Positioning System]] receiver provides precise [[orbit]] [[ephemeris]] data
* Laser [[retroreflector]] array works with ground stations to track the satellite and calibrate and verify altimeter measurements.

The Jason-1 satellite, its altimeter instrument and a position-tracking antenna were built in France. The radiometer, Global Positioning System receiver and laser retroreflector array were built in the United States.