Are any search technologies 100% accurate? What is the purpose of GPR? How much area can the GPR machine do per day? Keep, link to answer How accurate is the GPR equipment? Keep and answer What type of area can you not use GPR equipment? keep and answer What is the purpose of S4? How much area can the S4 machine cover per day? How accurate is the S4 system? What type of area can you not use S4? Can S4 be done before other search methods such as GPR or HHRDD?