SURVEYING

• SURVEYING

  • The art and science of determining angular and linear measurements to establish the form, extent, and relative position of points, lines, and areas on or near the surface of the earth or on other extraterrestrial bodies through applied mathematics and the use of specialized equipment and techniques.
• PLANE SURVEYING - a type of surveying where the earth is considered as a flat surface, and where distances and areas involved are of limited extent
• 1. GEODETIC SURVEYING - surveys of wide extent which take into account the spheroidal shape of the earth
• 1. CADASTRAL SURVEYS - closed surveys in urban and rural locations to determine and define property lines and boundaries, corners, and areas.
• 1. CITY SURVEYS - surveys in the city for planning expansions, locating property lines, fixing reference monuments, determining physical features of land, and preparing maps.
• 1. CONSTRUCTION SURVEYS - surveys done at a construction site to provide data regarding grades, reference lines, dimensions, ground configuration, and location and elevation of structures.
• 1. FORESTRY SURVEYS - survey in connection with forest management and mensuration, and the production and conservation of forest lands.
• 1. HYDROGRAPHIC SURVEYS - surveys made to map shore lines, chart the shape of areas underlying water surfaces, and measure the flow of streams.
• 1. INDUSTRIAL SURVEYS - known as optical tooling

  • surveys for ship building, construction and assembly of aircraft, layout and installation of heavy and complex machinery, and for industries requiring very accurate dimensional layouts.
• 1. MINE SURVEYS - surveys to determine the position of all underground excavations and surface mine structures, to fix surface boundaries of mining claims, determine geological formations, calculate excavated volumes, and establish lines and grades for other related mining work.
• 1. PHOTOGRAMMETRIC SURVEYS - survey which uses photographs taken with specially designed cameras either from airplanes or ground stations.
• 1. ROUTE SURVEYS - determination of alignment, grades, earthwork quantities, location of natural and artificial objects in connection with the planning, design, and construction of highways, railroads, pipelines, canals, transmission lines, and other linear projects.
• 1. TOPOGRAPHIC SURVEYS - surveys to determine the shape of the ground, the location and elevation of natural and artificial features upon it.
• • The extensive use of surveying instruments came during the early days of the Roman Empire.
• 1. ASTROLABE

  • invented by Hipparchus in 140 BC and further improved by Ptolemy
  • used to determine the altitude of stars
• 1. TELESCOPE

  • invented by Lippershey (1607)
  • Galileo constructed a refracting telescope for astronomical observations in 1609.
  • Only used in surveying after the cross hairs for fixing the line of sight were introduced
• 1. TRANSIT

  • invented by Young and Draper (1830)
  • the universal surveying instrument
• 1. SEMICIRCUMFERENTOR

  • used to measure and lay off angles and establish lines of sight by employing peep sights
• 1. PLANE TABLE

  • used in field mapping
  • consists of a board attached to a tripod and can be leveled or rotated to any direction
• 1. DIOPTRA

  • invented by Heron of Alexandria
  • used in leveling and measuring horizontal and vertical angles
• 1. ROMAN GROMA

  • for aligning or sighting points
  • consists of cross arms with suspended plumb lines fixed at right angles and pivoted upon a vertical staff.
• 1. LIBELLA

  • used by Assyrians and Egyptians
  • had an A-frame with a plumb line suspended from its apex
  • used to determine the horizontal
• 1. VERNIER

  • invented by Pierre Vernier
  • a short auxillary scale placed alongside the graduated scale of an instrument to determine the fractional parts of the main scale without interpolating.
• 1. DIOPTER

  • developed by Greeks in 130 BC
  • used for leveling, laying off right angles, and measuring horizontal and vertical angles.
• 1. COMPASS

  • for determining direction of lines and calculating angles between lines
  • consists of a magnetized steel needle which points at the magnetic north
• 1. GUNTER’S CHAIN

  • invented by Sir Edmund Gunter (1620)
  • used for taping distances
  • 66 ft long and contains 100 links
• 1. CHOROBATES

  • for leveling work
  • consists of a horizontal straight-edge about 6 m long, a groove 2.5 cm deep and 1.5 m long on top.
  • water is poured into the groove for leveling
• 1. MERCHET

  • for measuring time and meridian used by Chaldeans in 4000 BC
  • consists of a slotted palm leaf through which to sight and a bracket from which a plumb bob was suspended
• MEASUREMENT

  • process of determining the extent, size, or dimension of a particular quantity in comparison to a given standard
• 1. DIRECT MEASUREMENTS 

  • comparison of the measured quantity with a standard measuring unit (makes use of instruments to measure the quantity)
• 1. INDIRECT MEASUREMENTS

  • made when it is not possible to apply a measuring instrument directly to a quantity
• Meter


  A unit of length proposed in 1789 by French scientists to establish a system suitable for all times and all peoples, and which could be based upon permanent natural standards
• Original definition of meter

  1/10,000,000 of the earth's meridional quadrant
• English System officially phased out in the Philippines, only the modern metric system allowed to be used

  January 1, 1983
• Metric conversion signed into law in the Philippines by Pres. Marcos

  1978
• Metric system prescribed in the Philippines

  Use of the International System of Units (SI) as established by the General Conference on Weights and Measures and as modified by the local Metric System Board to suit Philippine Conditions
• 
  

  Radian – SI unit for plane angles (the angle subtended by an arc of a circle having a length equal to the radius of a circle)
• • Sexagesimal Units the degree, minute, second
• • Centesimal Units uses grads (360° = 400 grads)
  • the grad is divided into 100 centesimal minutes and the minute is divided into 100 centesimal seconds
• SURVEYING FIELD NOTES

  • constitute the only reliable and permanent record of actual work done in the field