🚀 go-pugleaf

In article <1992Oct31.003715.6327@sfu.ca> palmer@sfu.ca (Leigh Palmer) writes:
>Incidentally, I have heard that full available (to the US military) 
>precision can be deduced from data collected by these civilian devices if 
>one integrates over long time periods. The numbers do seem to jump *around* 
>the correct value, as I've observed in my backyard with one of these units, 
>owned by a friend. I've never done the integration. Can anyone provide 
>information about this rumor?

The noise being injected by DoD (the buzzphrase is selective availability)
is currently of a relatively simple type that can indeed be removed by
long-term averaging.  The geologists do this all the time; GPS is coming
in very handy indeed for geodetic work and studies of fault motion etc.,
where accuracy of a few centimeters is highly desirable.

The satellites and the ground stations *are* capable of introducing more
obnoxious forms of noise, which can't be averaged out.
-- 
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry