The optical phase modulators are integrated into the laser frequency control and servo system of the laser ranging interferometer, which is used in the metrology instrumentation of the two satellites.
The laser ranging interferometer onboard the Grace-FO satellites--aided by iXblue's optical phase modulators--will be able to better and more efficiently measure and monitor these vital global mass transports.
The aim of the Satellite Laser Ranging is to measure the distance between the SLR station and the centre of the mass of the satellite equipped with retroreflectors.
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The laser ranging
and interferometry measurements used to spot the wobble can also be used to measure the movement of tectonic plates and local changes in the earth's gravitational field, says coauthor Jean Dickey of the Jet Propulsion Laboratory.