_Sim.DataValid
"dvalid" log)(
 "A" eq$
{
%
% convert raw latitude and longitude
%
%%% "3427.8993N" !Sim.RawLat
%%% "08427.1379W" !Sim.RawLon
%
% stack: path seed prior-lat prior-lon
%
0.0 !Sim.Lat 0.0 !Sim.Lon
_Sim.RawLat
"lat" log)(
length 10 eq
{
 dup 1 right !Sim.LatPol
 *trakrawc
 _Sim.LatPol
 <
 |S -1.0 mul
 > pop
 !Sim.Lat
 _Sim.RawLon
"lon" log)(
 dup 1 right !Sim.LonPol
 *trakrawd
 _Sim.LonPol
 <
 |W -1.0 mul
 > pop
 !Sim.Lon
}
{
%
% problem with latitude and longitude
%
 pop
} ifelse

_Sim.Lat 0.0 eq
_Sim.Lon 0.0 eq
or
{
%
% did not get a proper calculation
%
 false
}
{
 _Sim.Msec !Sim.Valid
 _Sim.Lat !Sim.Vlat
 _Sim.Lon !Sim.Vlon
 true
} ifelse

}
{
 false
} ifelse
%
% stack: valid-locate
%