Surveying Instruments

• Extensive use of surveying instruments began during the Roman Empire.

Telescope

• Lippershey invented the telescope in 1607.
• Galileo constructed a refracting telescope for astronomical observations in 1609.
• Telescopes were only used in surveying after cross hairs were introduced for fixing the line of sight.

Transit

• Young and Draper invented the transit in 1830.
• The transit is a universal surveying instrument.
• It is used to establish a straight reference line, read angles, and measure distances.

Semicircumferentor

• It measures and lays off angles and establishes lines of sight using peep sights.

Plane Table

• It is used in field mapping.
• Consists of a board attached to a tripod that can be leveled or rotated.

Dioptra/Diopter

• Greeks developed it in 130 BC, and Heron of Alexandria invented it.
• It is used in leveling and measuring horizontal and vertical angles.

Roman Groma

• It aligns or sights points.
• The Roman Groma consists of cross arms with suspended plumb lines fixed at right angles and pivoted upon a vertical staff.

Libella

• Assyrians and Egyptians used the Libella.
• It had an A-frame with a plumb line suspended from its apex.
• It determined level and plumb, and acted as a square or ruler.

Vernier

• Pierre Vernier invented the Vernier scale.
• A Vernier is a short auxiliary scale placed alongside the graduated scale of an instrument.
• It determines the fractional parts of the main scale without interpolating.

Compass

• It determines the direction of lines and calculates angles between lines.
• It consists of a magnetized steel needle that points to magnetic north.

Gunter's Chain

• Sir Edmund Gunter invented it in 1620.
• It is used for taping distances.
• A Gunter's chain is 66 ft long and contains 100 links.

Chorobates

• It is used for leveling work.
• The Chorobates 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.

Merchet

• It measures time and meridian.
• Chaldeans used the Merchet in 4000 BC.
• The Merchet consists of a slotted palm leaf through which to sight and a bracket from which a plumb bob was suspended.

Meter Tape

• It is typically used to measure distance or size.
• One of the first documented tape measures arrived in 1829 and was patented by James Chesterman.

Measurements

• Measurement is the process of determining the extent, size, or dimension of a particular quantity in comparison to a given standard

Types of measurements

• Direct Measurements involve a comparison of the measured quantity with a standard measuring unit using instruments.
• Indirect Measurements are made when it is not possible to apply a measuring instrument directly to a quantity.

Units of Measurement

• Linear Measurements: Meter, feet, inches, kilometers, millimeters, centimeters.
• Area Measurements: Square meter, square feet, hectare.
• Volume Measurements: Cubic meter, cubic feet, cubic cm, etc.
• Angular Measurements:
• Sexagesimal units: 1 right angle = 90°, 1° = 60', 1' = 60".
• Centisimal units: 1 right angle = 100 grades, 1 grade = 100 minutes, 1 minute = 100 Seconds.

The Meter

• French scientists proposed it in 1789.
• It was to establish a system suitable for all times and peoples, based upon permanent natural standards.
• A treaty was signed in Paris on May 20, 1875, by representatives of 18 countries, creating the International Bureau of Weights and Measures.
• The treaty established the International Meter based on France (Paris) iron meter standardized in 1799.
• On January 1, 1983, the English System was officially phased out in the Philippines, and only the modern metric system was allowed to be used.

Surveying Field Notes include several components

• Sketches
• Tabulations
• Explanatory notes
• Computations
• Combination of the above

Information in Field Notes

• Title of fieldwork or the name of the project
• Time of day and date
• Weather conditions
• Names of groups and their designation
• A list of tools and equipment

Field Survey Party Roles

• Chief of Party: Responsible for the overall direction, supervision, and operational control of the survey party.
• Assistant Chief of Party: Assists the chief of party in accomplishing the tasks assigned to the survey party.
• Instrument Man: Sets up, levels, and operates the surveying instruments.
• Technician: Performs all computations of survey data and works out necessary computational checks in the field.
• Recorder: Keeps the record of all sketches, drawings, measurements, and observations taken in the field.
• Head Tape Man: Responsible for the accuracy and speed of all linear measurements with tape; carries the zero end of the tape ahead.
• Rear Tapeman: Assists the head tapeman during taping operations, holds the 30-m end or any intermediate meter mark of the tape during measurement.
• Flagman: Holds the flagpole or range pole at selected points as directed by the instrument man.
• Rodman: Holds the stadia or leveling rod when sights are to be taken on it.
• Pacer: Checks all linear measurements made by the tapeman; may also perform the job of the rodman.
• Axeman: Clears the line of sight of trees, brush, and other obstructions in wooded country.
• Aidman: Renders first aid treatment to members of the survey party who are involved in snake or insect bites, accidents, and other health issues; may also be designated as assistant instrument man.
• Utility Man: Renders other forms of assistance needed by the survey party or as directed by the chief of party.