surveying

• • "The science of making such measurement as are necessary to determine the relative position of points above, on, or beneath the surface of the earth, or establishing such points" - Brinker and Wolf
• • "Art of making such measurements of the relative position of points on the surface of the earth that, on drawing them to scale, natural and artificial features may be exhibited in their correct horizontal or vertical relationship" - Clarke
  • "Branch of applied mathematics which teaches the art of determining the area of any portion of the earth’s surface, the length and direction of the boundary lines, the contour for the surface, and of accurately delineating the whole on paper" - Webster
• Surveying Definition:

  • "Art of determining the position of points on or near the earth’s surface by means of measurements in the three elements of space; namely, distance, direction and elevation" - Rayner and Schmidt
  • "Art of measuring horizontal and vertical distances between objects, of measuring angles between lines, of determining the direction of lines, and of establishing points by predetermined angular and linear measurements" - Davis, Foote, Anderson, and Mikhail
• General Classification of Surveying:

  • Plane Surveying
  • Geodetic Surveying
• Plane Surveying:

  • Earth is considered a flat surface
  • Distances and areas involved are of limited extent
  • Exact shape of the earth is disregarded
  • Level line is considered mathematically straight for horizontal distances and directions
  • Plumb line direction is assumed to be the same at all points within the survey limits
  • All angles are considered to be plane angles
• Geodetic Surveying:

  • Surveys of wide extent taking into account the spheroidal shape of the earth
  • High precision surveys
  • Involves principles of geodesy
  • Calculations involve advanced mathematics like spherical trigonometry, calculus, and least squares theory
  • National character surveys for accurate base and topographic maps
• Types of Surveys:

  1. Cadastral

  2. City

  3. Construction

  4. Forestry and geological

  5. Hydrographic

  6. Industrial

  7. Marine

  8. Mine

  9. Photogrammetric

  10. Route

  11. Topographic

  12. Remote sensing

  13. As-built
• Cadastral Survey:

  • Closed surveys in urban and rural locations
  • Determine and define property lines, boundaries, corners, and areas
  • Fix boundaries of municipalities, towns, and provincial jurisdiction
• City Surveys:

  • Surveys in and near a city for planning expansions or improvements
  • Locating property lines, fixing reference monuments, determining physical features, and preparing maps
• Construction Survey:

  • Surveys at construction sites for data on grades, reference lines, dimensions, ground configuration, and location and elevation of structures
• Forestry and Geological Survey:

  • Survey for forest management, mensuration, and production and conservation of forest lands
  • Uses surveying for boundary locations, timber cruising, topography, and geological map preparation
• Hydrographic Surveys:

  • Surveying of streams, lakes, reservoirs, harbors, oceans, and other bodies of water
  • Mapping shorelines, charting areas under water surfaces, and measuring stream flow for navigation, water supply, flood control, and more
• Industrial Survey:

  • Also known as optical tooling
  • Uses surveying techniques in shipbuilding, construction, assembly of aircraft, layout of machinery, and industries requiring accurate dimensional layouts
• Marine Survey:

  • Related to hydrographic surveys but covers a broader area
  • Includes surveys for offshore platforms, tides theory, and preparation of hydrographic maps and charts
• Mine Survey:

  • Determines position of underground and surface mine structures
  • Fixes surface boundaries of mining claims, determines geological formations, calculates excavated volumes, and establishes lines and grades for mining work
• Photogrammetric Survey:

  • Uses photographs from specially designed cameras in airplanes or ground stations
  • Measurements from photographs used with limited ground surveys
• Route Survey:

  • Determines alignment, grades, earthwork quantities, location of objects for planning, design, and construction of linear projects like highways, railroads, pipelines, and more
• Topographic Survey:

  • Determines ground shape, location, and elevation of natural and artificial features
  • Includes hills, mountains, rivers, lakes, roads, buildings, towns, and bridges
• Remote Sensing Survey:

  • Aerial survey using cameras or sensors in aircraft or satellites
• As-Built Survey:

  • Conducted after construction completion to provide positions and dimensions of project features as constructed
  • Checks if construction followed the design plan
• Surveying is the process of determining the extent, size, or dimension of a particular quantity in comparison to a given standard
• Measurements in surveying are usually concentrated on angles, elevations, times, lines, areas, and volumes
• The surveyor's role is to design surveys, plan out, and execute the required field operations
• No exact or true measurement is ever possible in surveying, and the true value of a measured quantity is never known
• Direct measurements involve comparing the measured quantity with a standard measuring unit employed for measuring that kind of quantity
• Examples of direct measurements include applying a wire or tape to a line, determining horizontal or vertical angles with a transit, or fitting a protractor between two intersecting lines to determine the intersection angle
• Indirect measurements are done when it is not possible to apply a measuring instrument directly to a quantity to be measured
• In indirect measurements, the observed value is determined by its relationship to some other known values
• The meter is the international unit of linear measure, redefined in October 1960 to equal 1,650,763.73 wavelengths of orange-red light produced by burning krypton at a specified energy level
• The International System of Units (SI) is used for surveying, with units such as meter (m) for linear measure, square meter (m²) for areas, cubic meter (m³) for volumes, and radian (rad) for plane angles
• SI prefixes are used for forming multiples and submultiples of different units, including prefixes for larger quantities and whole units like tera, giga, mega, kilo, hecto, and deka
• SI prefixes are also used for smaller quantities and subunits, such as femto, atto, zepto, yocto, ronto, and quecto
• Linear, area, and volume measurements include conversions like 1 kilometer (km) = 1,000 meters, 1 meter (m) = 1,000 millimeters, and 1 decimeter (dm) = 10 centimeters
• Angular measurements in surveying use the SI unit radian, where 1 radian equals 57.2958 degrees and 2π radians equal 360 degrees
• Significant figures are important in recording results from measurements, with rules for determining the number of significant figures in a value
• General rules for significant figures include zeroes between other significant figures being significant, zeroes immediately to the right of the decimal not being significant for values less than one, and zeroes at the end of decimal numbers being significant