What are the disadvantages of using GPS in surveying?

disadvantages of using GPS in surveying is in highly conjusted or buildup areas where the not open sky so their is he not received satellite so create in GPS locations not perfact as compare to total Station or DGPS.   

The inability to perform geodetic survey in tunnels, through wooded areas or some valleys.

Also You couldn't measure any points near walls, pillars corners, etc. And accuracy is better when using total stations that could be necessary while monitoring or high-precision objects construction or mounting.