Dear UK Geophysicists, I've been kind-of aware of the potential problem laid out below, but this is the first time I've seen it laid out in cogent terms. many of us are critically dependent on GPS/Glonass/Galileo. And it seems there's a commercial initiative which is all too likely to "go global" and significantly compromise scientific use of satellite location which uses very similar frequencies. Note the ITU initiative. We may be needing to raise some political clout.
Does anybody know how to ring the right bells in the UK govt sector?
Regards
Alan Reid
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Begin forwarded message:
> From: Clark Jorgensen <[log in to unmask]>
> Date: 1 August 2011 15:17:37 GMT+01:00
> To: "[log in to unmask]" <[log in to unmask]>
> Subject: [GRVMAG] LightSquared and differential GPS
> Reply-To: [log in to unmask]
>
> Dear Colleagues:
>
> Part of my work is doing differential GPS/gravity surveys for various
> clients. Because I use a GPS system, I started subscribing to the
> magazine GPS World (www.gpsworld.com) which is a very informative and free
> publication (at least in the US). The magazine is quite good in technical
> content describing upgrades to the Russian GLONASS system, the development
> of the European Galileo system, and the switch of the US two frequency
> system to three frequencies.
>
> I have read the articles of the switch of the US GPS system from two to
> three frequencies with trepidation and excitement. The switch will make
> all of the older, very expensive, two frequency systems (like mine)
> inoperable. But the new three frequency system will, supposedly, have the
> ability to give centimeter grade accuracy solutions under tree cover.
> Companies like Trimble, Leica, Topcon, and Sokkia back engineered the
> differential solutions to the military clandestine frequency and patented
> their solutions. The new three frequency system will only have one
> military clandestine channel so companies like Garmin and Magellen should
> be able to build very cheap two frequency differential systems. The
> switch from two to three frequencies has been long delayed because of the
> cost of the wars in Afghanistan and Iraq but now is moving forward again
> and appears certain to occur.
>
> In the past several months another severe and more ominous threat has
> occurred to differential GPS. A company called LightSquared
> (www.lightsquared.com) has proposed the introduction a land and satellite
> based 4G mobile phone service to the US government. Unfortunately this
> service interferes with all GNNS satellite signals (GPS, GLONASS, and
> Galileo). They have recently amended their proposal so their signal won't
> interfere with nondifferential GPS users, but will still wipe out
> differential GPS usage. Their proposal is now receiving greater US
> government scrutiny but they are also appealing to the International
> Telecommunications Union which would allow them to circumvent US law. If
> their system is allowed to be launched it will wipe out differential GPS
> usage. It is possible that GPS companies will be able to develop jammers
> that will allow GPS to operate, but I don't know if this is possible, and
> if it is possible, how much it will add to the cost of a GPS system.
>
> Even if you don't directly use differential GPS in your business, this
> proposal will drastically affect the way many geophysical surveys are
> conducted. I ask you to become apprised of the issue and contact your
> governmental representatives to voice your concerns.
>
> Thanks,
> Clark
>
> --
> Clark Jorgensen
> Big Sky Geophysics
> P.O. Box 353
> Bozeman, MT 59771
> USA
> +1 (406) 587-6330 phone/fax
> +1 (406) 580-9718 mobile
> [log in to unmask]
> www.bigskygeo.com
> skype: bigskyclark
>
Alan B Reid PhD
Reid Geophysics Ltd
7 Keymer House
Michel Grove
Eastbourne BN21 1JZ
UK
Phone: +44 (0) 1323 735520
Mobile: +44 (0) 781 692 4728
Skype Name: alanbarryreid
mailto: [log in to unmask]
web: http://www.reid-geophys.co.uk
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