In situ data collection:
• The data collected directly in the field. This can be a time-consuming, expensive, and
inaccurate process.
• Problems associated with in situ data collection:
A sample design: does not capture all of the spatial variability of the phenomena under
investigation;
Improper operation: operating in situ measurement instrument improperly;
Uncalibrated in situ measurement: using an in situ measurement instrument that has not
been calibrated properly.