201505 May/June 2015

Farm Vehicle Automation

Francisco Rovira-Más, Agricultural Robotics Laboratory, Universidad Politécnica de Valencia

Now that we have had GNSS-driven precision in the fields for nearly 20 years, with widespread and growing acceptance by farm vehicle manufacturers and farmers, what lies ahead for precision agriculture?

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By Inside GNSS

Are there special considerations for dealing with raw GNSS data?

Q: Are there special considerations for dealing with raw GNSS data?

A: Most GNSS users are only interested in position, velocity, and/or time (PVT) information provided by a receiver. In fact, most mass-market GNSS receivers (e.g., those in cell phones or in your vehicle) only provide PVT information along with some supporting data (such as the number of satellites tracked, dilution of precision, course over ground, and so forth).

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By Inside GNSS
May 20, 2015

Estimating the Short-Term Stability of In-Orbit GNSS Clocks

Global navigation satellite systems provide position, velocity, and time (PVT) solutions to users whose receivers calculate position based on one-way ranging from satellites. As is well-understood, a key step in the positioning process involves a determination of the difference between the time of signal transmission identified in the satellite’s broadcast navigation message and the time of its reception by user equipment.

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By Inside GNSS

Thinking Small

Equations 2, 7, 8, 9, 10 & 11

Unmanned aerial vehicles (UAV) are finding increased application in both domestic and governmental applications. Small UAVs (maximum take off weight less than 20 kilograms) comprise the category of the smallest and lightest platforms that also fly at lower altitudes (under less than 150 meters).

Designs for this class of device have focused on creating UAVs that can operate in urban canyons or even inside buildings, fly along hallways, and carry listening and recording devices, transmitters, or miniature TV cameras.

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By Inside GNSS

Riding High with EGNOS

The Pink City from up there. Photo by Peter Gutierrez

Judging from the variety of questions being asked at a recent EGNOS flight demonstration, the European Geostationary Navigation Overlay Service (EGNOS) remains something of a mystery for many of Europe’s leading aviation writers.

EGNOS, you say? What’s EGNOS?

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By Inside GNSS
May 14, 2015

USAF Draft RFP Would Re-Open Competition for GPS Satellite Launch Services

GPS Block IIF-5 on its way from Cape Canaveral on February 20, 2014. Photo by Ben Cooper, United Launch Alliance

[Updated May 26, 2015] The U.S. Air Force released a draft request for proposal (RFP) yesterday (May 13, 2015) for GPS III Launch Services, including launch vehicle production, mission integration, and launch operations. The Space Exploration Technologies Corporation — better known as SpaceX and headed by Elon Musk — may well enter the competition.

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By Inside GNSS
May 6, 2015

Lockheed Completes Integration of First GPS III Spacecraft

In April, Lockheed Martin fully integrated the U.S. Air Force’s first next-generation GPS III satellite at the company’s Denver, Colorado–area satellite manufacturing facility. The first in a design block of new, more powerful and accurate GPS satellites, GPS III Space Vehicle One is now preparing for system-level testing this summer. Lockheed Martin photo

Lockheed Martin has finally been able to announce victory in its effort to complete integration of the first GPS Block III satellite.

Integration took place last month at the company’s GPS III Processing Facility near Denver, Colorado, bringing together the system module — which includes the navigation payload that performs the primary positioning, navigation, and timing mission — the functional bus containing the electronics that manage all satellite operations, and the propulsion core that enables the satellite to maneuver for operations on orbit.

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By Inside GNSS