Towards a Sound National Policy for Civil Location and Time Assurance
Incidents of GNSS interference and jamming are increasing in the United States. Successful spoofing of civil GPS signals has been demonstrated.
What risks do these pose for companies and individuals using or relying on space-based positioning, navigation, and timing? A signals and waveform expert sizes up the problem and proposes some solutions.
Using Inertial and Magnetic Field Sensors
Determination of horizontal attitude poses a general problem for navigation applications, especially those using small aerial platforms and requiring low-cost solutions. A team of German engineers are exploring a method that combines accelerometers, gyroscopes, and a magnetic field sensor with a GNSS compass to provide a multi-sensor attitude system for portable, small-sized launcher applications. Promising results include bridging GNSS dropouts as well as enhanced integrity monitoring.
What’s not to like about GPS?
It’s free, it’s worked great — without
failure, really — for nearly 20 years, and it has delivered to the
world’s citizens an affordable, accurate, and widely available
capability for precise location and timing unprecedented in human
The Check is in the Mail
Not only have the GPS civil program funds been held up for months, but
when the promised amount finally arrives, it will —again— be far short
of what was budgeted.
If we were to think of the GNSS enterprise as a ship sailing the
high seas of space, then space weather expert Genene Fisher would be up in the
crow’s nest, on the lookout for asteroids instead of icebergs.
for Improved Single-Frequency Precise Positioning
Single-frequency positioning can undoubtedly be improved with the deployment of new GNSS systems and the accompanying availability of new signals. Among various innovations, the Galileo E5 broadband signal deserves special attention. This article demonstrates the expected performance of E5 for selected land applications and precise orbit determination of low Earth orbiting satellites.
GNSS Data Points and Factoids to Amuse and Inform
In this issue: Third GPS IIF, Galileo on a roll, how to get away in the UK, Scottish toilets and property lines in India.
When a Signal in Space Isn’t Enough
Five to ten meters might seem like pretty good real-time accuracy. But not when you’re landing an airplane or guiding a farm vehicle through a field.