RASTER and real coordinates problem

[Antonio]

hi all,

I've a raster image (600*400) of a harbour ... in the map file i MUST specify

EXTENT 0.0 0.0 600.0 400.0

(correct ?)
...
the real coordinates of the gps are between -9.10 41.20 -9.55 42.30 (for
example) ...

HOW can I calculate the real position of the boats on the map ?

I'm tryin projection, but I'm not able to resolve ...

documentation ? links ? etc ...

tanks in advance ...

-- 
#include <stdio.h>
int main(void){char c[]={10,65,110,116,111,110,105,111,32,98,97,114,98,111,110,
101,32,60,104,105,110,100,101,109,105,116,64,116,105,115,99,97,108,105,110,101,
116,46,105,116,62,10,10,0};printf("%s",c);return 0;}