Geodesy, Geodetic or Geospatial data are composed of points, lines and area relations which rich attributes.
In other word, surveyor are usually faced with the problem of estimating unknown quantities (paramaters). This is done through collecting several measurement known as observations.
Then adopting the appropriate mathematical model relating both observation and unknowns.
Observation generally requires some form instrumentations that is used by an observer in certain environment.
All observations contain errors. An error is different between an observation of a quantity and the true value. True value can never be known.
True error (e) = l – t, where l is observed value and t is true value
Both quantities, e and t can be estimated ..