It is in the thread "beyond visual range 8 km"
http://rapidshare.de/files/3185013/Sensors.dat.html
(goes to data/Library)
Look for
CCIP link to it. It will increase you spotting range to the maximum of 10 km; but no more. To spot further will need to increase the 'World Size' larger.
There is a discussion
Manuel Ortega in the Scene.dat file which sets clipping distance. It will put more load on youR CPU. It defines the basic world parameters.