Horizontal accuracy of survey and GPS derived
road maps were compared with regard to
the map created by the NCC as base map. In
the forest environment tree canopies and stems
distort or break satellites signal and can result
limited access to signals (Rodríguez-Pérez et
al. 2007). On the other hand, there are two
types of errors that may take place in survey
technique: 1- User errors in measuring phase,
2- User errors in delineation phase (Tammadoni
1987). So if the user is poorly trained or
prone to error, obvious errors may occur. One
should keep in mind that if the user is well
trained, the results will have high accuracy