[Tagging] Micro Mapping, was Race track

John Smith deltafoxtrot256 at gmail.com
Mon Feb 1 03:33:59 GMT 2010

On 1 February 2010 12:42, John F. Eldredge <john at jfeldredge.com> wrote:
> It may be difficult to obtain GPS equipment that has accurate altitude data.  The GPS satellite system is maintained by the US military, and I have read that the altitude information available to civilian equipment has deliberate errors, in order to make it harder for terrorists, or non-US militaries, to use that equipment to plan out artillery attacks in advance.  The equipment used by the US military makes use of a more accurate, but encrypted, altitude signal.  In the US, at least, such equipment is classified and not legally available to civilians.

Long term people will work out a way round the altitude problem if the
need is great enough, just like they worked round the horizontal
accuracy problem, even prior to SA being turned off people had a
solution for over coming SA errors, which may have lead to SA being
turned off earlier than originally planned.

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