26
EXECUTION
OF SURVEYS
SOURCES OF ERROR
SOURCES OF ERROR
Errors may be
characterized as random, systematic, or blunders
›Systematic error represents the effect of consistent inaccuracies in the
instruments or in the leveling
procedures
›Systematic error may
be small in a single measurement; it accumulates when measurements made under similar circumstances are
totaled
›Therefore, it can
result in a significant discrepancy in the height differences measured between two control points by different
leveling systems and/or routes
›For leveling to
provide accurate height differences, systematic error must be minimized, either by procedure or by applying
corrections to the data
