Question

Which of the following is a basic principle of surveying?

• A. Satellite imagery analysis
• B. Data interpolation
• C. Triangulation
• D. Spectral analysis

Hint:

• Basic principles of surveying guide how measurements are made and control is established.
• Triangulation is a fundamental method where a network of triangles is used. Angles are measured, and a baseline length allows calculation of other lengths and positions.
• Other key principles/methods include working from whole to part, traversing, and trilateration.
• Satellite imagery analysis, data interpolation, and spectral analysis are tools or data processing techniques, not foundational surveying principles for position fixing in the classical sense.

Answer 1

The Correct Option is C

Surveying is the science and art of determining the terrestrial or three-dimensional positions of points and the distances and angles between them. Several fundamental principles and techniques underpin surveying practices.

• Working from the whole to the part: This principle involves establishing a network of control points with high accuracy covering the entire survey area first, and then densifying this network with points of lower accuracy. This helps to control the accumulation of errors.
• Independent Checks: All measurements should be subject to checks to detect mistakes and errors.
• Consistency of Accuracy: The accuracy of measurements should be consistent with the purpose of the survey.
• Methods of Locating Points: Points are typically located by measurements from at least two known reference points. Common methods include:
  • Triangulation (option c): A classic surveying technique where the area to be surveyed is covered by a network of triangles. The angles of these triangles are measured precisely, and the length of at least one side (the baseline) is measured. Using trigonometry (sine rule), the lengths of the other sides of the triangles, and thus the positions of the vertices, can be calculated. This was historically a primary method for establishing large-scale control networks.
  • Traversing: A series of connected lines whose lengths and directions are measured.
  • Trilateration: Measuring only the lengths of the sides of a network of triangles.
  • Offsets: Measuring distances perpendicular to a baseline to locate points.
  • Radiation/Polar Coordinates: Measuring an angle and a distance from a known point.

Option (c) Triangulation is a fundamental and historically significant principle/technique in surveying for establishing control and determining positions. Other options: Option (a) Satellite imagery analysis: A tool used in modern surveying and remote sensing, but it's an application of technology rather than a basic foundational principle in the same way as triangulation. Option (b) Data interpolation: A mathematical technique used to estimate values at unmeasured locations based on known values at measured locations (e.g., creating contour lines). It's a data processing step, not a basic field surveying principle. Option (d) Spectral analysis: Relates to analyzing the spectral properties of light or other radiation, primarily used in remote sensing and spectroscopy, not a basic principle of traditional ground surveying for position determination. \[ \boxed{\text{Triangulation}} \]