Question

Positional error is error due to:

• A. Incorrect labelling of features
• B. Imprecision in coordinate registration
• C. Biasness in shapefiles
• D. Elevation changes

Hint:

Remember: \[ \boxed{ \text{Wrong Coordinates} \Longrightarrow \text{Positional Error} } \] Coordinate registration and georeferencing accuracy directly affect positional accuracy.

Answer 1

The Correct Option is B

Concept: Positional error is the difference between the actual ground location of a feature and its recorded location in a GIS database. It mainly arises from inaccurate coordinate registration during data collection, digitization, or georeferencing.

Step 1: Understand positional error. The position of a feature is represented by its coordinates. If the recorded coordinates differ from the true coordinates, \[ \boxed{ \text{Positional Error} = \text{Recorded Position} - \text{True Position} } \] Possible causes include:
• GPS measurement errors.
• Digitization inaccuracies.
• Incorrect georeferencing.
• Coordinate transformation errors.

Step 2: Evaluate the options.
• Incorrect labelling affects attribute accuracy, not position.
• Imprecision in coordinate registration directly changes feature location.
• Biasness in shapefiles is not a standard positional error.
• Elevation changes do not produce positional error in planimetric coordinates. Hence, \[ \boxed{\text{Positional error results from imprecision in coordinate registration}.} \] Therefore, the correct option is \[ \boxed{(B).} \]