Survey tool system for blast hole drilling rigs

A method for surveying deviation of a previously drilled uphole from a selected hole path with a survey tool system, said method comprising:

• co-operating an assembly of drill pipe sections with said previously drilled uphole, the previously drilled uphole having an open end at a lower elevation than a terminal end of the previously drilled uphole;
• collecting survey data from at least one sensor included within the assembly of drill pipe sections, said survey data including data correlated with deviation of said previously drilled hole from said selected hole path;
• and
• processing said survey data collected from said at least one sensor and determining deviation of said previously drilled hole from said selected hole path,
• characterized in that said at least one sensor is included within a survey tool assembly connected to a frontmost end of the assembly of drill pipe sections and configured to form a terminal end of the assembly of drill pipe sections, and characterized in that collecting of survey data follows completion of a drilling operation and replacement of a drilling bit assembly with said survey tool assembly.