A professional who verifies accuracy and completeness of topographical maps from aerial photographs and specifications. Responsibilities include:

• Views photographs and other reference materials, such as old maps and records and examines corresponding area of map to verify correct identification of specified topographical features and accuracy of contour lines.
• Verifies correct location and accuracy of scaled distances between control points and reference lines.
• Examines reference materials to detect omission of topographical features, poor register, or other defects in photography or draftsmanship.
• Marks errors and makes corrections, such as numbering grid lines or lettering names of rivers or towns.