Japan’s Plan for Centimeter-Resolution GPS

A $1.2 billion system of satellites and ground stations would give unprecedented accuracy

3 min read
Japan’s Plan for Centimeter-Resolution GPS
Pacific Constellation: Four QZSS satellites will orbit in such a way that at least one is always directly over Japan. Three reserves will hang at the equator.
Illustration: Erik Vrielink

A stranger to Tokyo could easily get lost in its urban canyons. And GPS navigation, stymied by low resolution and a blocked view of the sky, might not be much help. But that won’t be the case after 2018. Engineers at Tokyo-based Mitsubishi Electric Corp. report that they’re on track to start up the first commercial, nationwide, centimeter-scale satellite positioning technology. As well as spot-on navigation, the technology will also usher in a variety of innovative new applications, its proponents say.

Named Quazi-Zenith Satellite System (QZSS), it is designed to augment Japan’s use of the U.S.-operated Global Positioning System (GPS) satellite service. By precisely correcting GPS signal errors, QZSS can provide more accurate and reliable positioning, navigation, and timing services.

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Two men fix metal rods to a gold-foiled satellite component in a warehouse/clean room environment

Technicians at Northrop Grumman Aerospace Systems facilities in Redondo Beach, Calif., work on a mockup of the JWST spacecraft bus—home of the observatory’s power, flight, data, and communications systems.

NASA

For a deep dive into the engineering behind the James Webb Space Telescope, see our collection of posts here.

When the James Webb Space Telescope (JWST) reveals its first images on 12 July, they will be the by-product of carefully crafted mirrors and scientific instruments. But all of its data-collecting prowess would be moot without the spacecraft’s communications subsystem.

The Webb’s comms aren’t flashy. Rather, the data and communication systems are designed to be incredibly, unquestionably dependable and reliable. And while some aspects of them are relatively new—it’s the first mission to use Ka-band frequencies for such high data rates so far from Earth, for example—above all else, JWST’s comms provide the foundation upon which JWST’s scientific endeavors sit.

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