<s>
Map	B-General_Concept
matching	I-General_Concept
is	O
the	O
problem	O
of	O
how	O
to	O
match	O
recorded	O
geographic	O
coordinates	O
to	O
a	O
logical	O
model	O
of	O
the	O
real	O
world	O
,	O
typically	O
using	O
some	O
form	O
of	O
Geographic	B-Application
Information	I-Application
System	I-Application
.	O
</s>
<s>
Matching	O
observations	O
to	O
a	O
logical	O
model	O
in	O
this	O
way	O
has	O
applications	O
in	O
satellites	B-Application
navigation	I-Application
,	O
GPS	O
tracking	O
of	O
freight	O
,	O
and	O
transportation	O
engineering	O
.	O
</s>
<s>
Map	B-General_Concept
matching	I-General_Concept
algorithms	O
can	O
be	O
divided	O
in	O
real-time	B-General_Concept
and	O
offline	O
algorithms	O
.	O
</s>
<s>
Real-time	B-General_Concept
algorithms	O
associate	O
the	O
position	O
during	O
the	O
recording	O
process	O
to	O
the	O
road	O
network	O
.	O
</s>
<s>
Real-time	B-General_Concept
applications	I-General_Concept
can	O
only	O
calculate	O
based	O
upon	O
the	O
points	O
prior	O
to	O
a	O
given	O
time	O
(	O
as	O
opposed	O
to	O
those	O
of	O
a	O
whole	O
journey	O
)	O
,	O
but	O
are	O
intended	O
to	O
be	O
used	O
in	O
'	O
live	O
 '	O
environments	O
.	O
</s>
<s>
The	O
earliest	O
approached	O
to	O
solve	O
the	O
map	B-General_Concept
matching	I-General_Concept
problem	O
based	O
on	O
similarity	O
between	O
points	O
 '	O
curve	O
and	O
the	O
road	O
curve	O
.	O
</s>
<s>
Map	B-General_Concept
matching	I-General_Concept
is	O
described	O
as	O
a	O
hidden	O
Markov	O
model	O
where	O
emission	O
probability	O
is	O
a	O
confidence	O
of	O
a	O
point	O
to	O
belong	O
a	O
single	O
segment	O
,	O
and	O
the	O
transition	O
probability	O
is	O
presented	O
as	O
possibility	O
of	O
a	O
point	O
to	O
move	O
from	O
one	O
segment	O
to	O
another	O
within	O
a	O
given	O
time	O
.	O
</s>
<s>
Map	B-General_Concept
matching	I-General_Concept
is	O
implemented	O
in	O
a	O
variety	O
of	O
programs	O
,	O
including	O
the	O
open-source	B-Application
GraphHopper	B-Language
and	O
Open	B-Language
Source	I-Language
Routing	I-Language
Machine	I-Language
routing	O
engines	O
.	O
</s>
