  Baseline azimuth calculation using GPS carrier phase data can be achieved in
a classic way by using two or more geodetic synchronized GPS receivers. Such
system includes dedicated expensive components and thus is not applicable to
many uses. The development of low cost GPS receivers have come to a point where
good quality carrier phase measurements are available and double differencing
systems utilizing these receivers have proven feasible. Inexpensive receivers
like this, combined with attitude determination algorithm, can make accurate
attitude determination using GPS accessible to everyone.
  Our project consisted of developing a low cost attitude determination system
utilizing 2 Fastrax off-the-shelf receivers. Phase and code data from the
receivers is processed, filtered and used for attitude determination using
double-difference algorithm. Possible applications for such systems are for
example: * Civilian - search and rescue equipment * Industrial - low cost
geodetic measurement * Military - inexpensive weapon guidance system
