Use the term "GPS receiver" rather than "sensor".

Avoid referring to WGS84 geoid and getting into the whole
ellipsoid/geoid bit, because that's way too complicated for the first
paragraph.  Hold my nose and leave "mean sea level" (in modern height,
there's no such thing).

1 files changed, 8 insertions, 7 deletions

diff --git a/www/gps-hacking.html b/www/gps-hacking.html
index 9bec6628..4a2ff097 100644
--- a/www/gps-hacking.html
+++ b/www/gps-hacking.html
@@ -78,13 +78,14 @@ GPS works and ending with architectural suggestions about how to use
 <h2>How GPS Works</h2>
 
 <p>First, the basics of how GPS works.  It depends on the fact that
-satellite orbits can be modelled accurately.  A GPS sensor is a specialized
-computer that knows about the orbits of GPS satellites, and in
-particular can predict exactly where each satellite will be at any
-given time with respect to the fixed Earth.  (For those of you who
-enjoy such details, what they actually predict is each satellite's
-position with respect to an imaginary ellipsoid called the "WGS 84
-geoid" which closely fits the mean sea level of Earth.)</p>
+satellite orbits can be modelled accurately.  A GPS receiver is a
+combination of a radio receiver and computer that receives timing
+signals and orbit information from GPS satellites, and in particular
+can compute exactly where each satellite will be at any given time
+with respect to the fixed Earth.  (For those of you who enjoy such
+details, what they actually predict is each satellite's position with
+respect to a coordinate system known as WGS84 which closely fits the
+mean sea level of Earth.)</p>
 
 <p>Although the term <strong>GPS</strong> properly refers only to the
 system operated by the United States Air Force (also