feature to combine location and time

[andreaskutka]

Problem

Location and time are evaluated independently. "Bad" locations (fakes, GPS recorded later) may not flag as location based anomalies, e.g. if location density is high or interviewers sleep in survey areas.

Solution
Location and time can be evaluated combined, e.g.

• looking for outliers by day (and interviewer)
• for all locations for one interviewer in one day, calculate the distance or speed between points and flag anomalies