Feeds

New GPS sats to lack Selective Availability

Availability will still be selective though

Choosing a cloud hosting partner with confidence

The US military announced yesterday that it will no longer procure Global Positioning System (GPS) satellites with the capability for worldwide civil sat nav degradation.

In a release dated yesterday, the Pentagon confirmed that "this capability, known as Selective Availability (SA), will no longer be present in the next generation of GPS satellites".

Until 2000, the accuracy of the GPS civil signal was reduced using SA, so that a normal sat nav receiver would be accurate to only 100 metres or so. There was and remains a separate military signal, encrypted so only those with appropriate keys - such as the US forces and their allies - can use it.

Despite SA, many civil users were able to achieve excellent accuracy using a technique known as Differential GPS, in which a ground station at a known location would calculate the SA error and transmit corrections to a mobile civil receiver in real time.

SA was switched off in 2000 on the orders of President Clinton, but it remained an option. In the years since, the US government has sought to assure civil GPS users that SA would never be used again, but its presence has remained a concern.

Now it has been confirmed that the next generation of satellites will not have SA built in. According to the Pentagon: "While this action will not materially improve the performance of the system, it does reflect the United States' strong commitment to users by reinforcing that this global utility can be counted on to support peaceful civil applications around the globe."

This announcement may reassure users somewhat, but the GPS civil signal still isn't a given. America will retain the option to degrade or deny it altogether over limited areas, and this was always much more likely to happen than the relatively blunt instrument of degrading performance worldwide.

The European Commission is just about to make its case for pushing ahead with the proposed new Galileo Euro sat nav constellation. One might speculate that the timing of this American announcement isn't a coincidence. ®

Security for virtualized datacentres

More from The Register

next story
Ex-US Navy fighter pilot MIT prof: Drones beat humans - I should know
'Missy' Cummings on UAVs, smartcars and dying from boredom
Facebook, Apple: LADIES! Why not FREEZE your EGGS? It's on the company!
No biological clockwatching when you work in Silicon Valley
The 'fun-nification' of computer education – good idea?
Compulsory code schools, luvvies love it, but what about Maths and Physics?
Happiness economics is bollocks. Oh, UK.gov just adopted it? Er ...
Opportunity doesn't knock; it costs us instead
'Cowardly, venomous trolls' threatened with TWO-YEAR sentences for menacing posts
UK government: 'Taking a stand against a baying cyber-mob'
Doctor Who's Flatline: Cool monsters, yes, but utterly limp subplots
We know what the Doctor does, stop going on about it already
Sysadmin with EBOLA? Gartner's issued advice to debug your biz
Start hoarding cleaning supplies, analyst firm says, and assume your team will scatter
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.