[ntp:questions] Re: First Galileo satellite launched

Marc Brett marc at fordson.demon.co.uk
Thu Dec 29 10:43:01 UTC 2005


On Thu, 29 Dec 2005 07:51:19 +0100, Terje Mathisen
<terje.mathisen at hda.hydro.com> wrote:

>David L. Mills wrote:
>> GLONASS and P-code capabilities are available for some high-end geodetic
>> receivers. Neither one of us can afford to buy them. By the way, GLONASS
>>  uses a different geodetic than GSS WG84. Their web site says a
>> parameter conversion is not available. I assume Galileo will use WG84. I
>> see GLONASS uses FDMA, while GPS and presumably Galileo uses CDMA. I
>> assume that would make multichannel receivers for GLONASS hugely expensive.
>
>Yes.
>
>Check Ashtech. (Currently owned by Thales Navigation):
>
>	http://products.thalesnavigation.com/en/
>
>Used on all Royal Carribean cruise ships, some of them were installed by
>a friend of mine.
>
>The (electronic) maps they use are still 10+ m wrong in some harbours
>though!

Or they can be 17+ miles! wrong if the antenna cable is disconnected and nobody
notices:

http://catless.ncl.ac.uk/Risks/24.03.html#subj4

"the level of faith placed in a GPS and chartplotter scares me."




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