CE215

60問 • 1年前

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The science of gathering information about the physical Earth.

Surveying

Includes measurement of distances, determining relative positions of points on or beneath the surface of the earth, or establishing such points.

Surveying

Types of Surveys:

Cadastral, Construction, Hydrographic, Industrial, Mine, Photogrammetric, Route, Topographic

Relates to laws of land ownership.

Cadastral Surveys

It includes establishment or re-establishment of real property boundaries.

Cadastral Surveys

Often called "stake-out", "layout" or "setting out".

Construction Surveys

It is an essential part of construction that is performed to establish reference points and markers that will guide the construction.

Construction Surveys

It includes mapping bodies of water such as lakes, rivers, etc.

Hydrographic Surveys

It includes measurement of features such as discharge, etc.

Hydrographic Surveys

A sub-discipline of surveying which requires high accuracy and precision.

Industrial Surveys

It includes alignment of machineries and optical tooling.

Industrial Surveys

The practice of measuring and mapping on-ground or underground points for the purpose of exploiting and utilizing mineral deposits.

Mine Surveys

Obtains reliable spatial information from photographic images (may it be aerial or terrestrial).

Photogrammetric Surveys

Provides the data needed to determine horizontal and vertical alignment, and even earthwork quantities, for the design of linear structures such as roads, railways, pipelines, etc.

Route Surveys

Are used to map natural and/or man-made features on the ground as well as obtain elevations.

Topographic Surveys

Consists of counting the number of steps or paces in a required distance.

Pacing

Defined as the length of a step in walking.

Pace

A double step.

Stride

The distance covered by one pace.

Pace Factor

Determined by dividing the known distance by the average number of paces required to traverse it.

Pace Factor

The difference between the observed value and the true value of a measurement.

Error

Are caused by variations in wind, temperature, humidity, atmospheric pressure, atmospheric refraction, gravity, and magnetic declination. An example is a steel tape whose length varies with changes in temperature.

Natural Errors

Result from any imperfection in the construction or adjustment of instruments and from the movement of individual parts. For example, the graduations on a scale may not be perfectly spaced, or the scale maybe warped.

Instrumental Errors

Arise principally from limitations of the human senses of sight and touch.

Personal Errors

Types of Errors:

Natural, Instrumental, Personal

Refers to the degree of refinement or consistency of a group of observations and is evaluated on the basis of discrepancy size.

Precision

Denotes the absolute nearness of observed quantities to their true values.

Accuracy

Are made in a variety of lengths, materials, and weights.

Measuring Tapes

The process of directly measuring distances with the use of a graduated tape.

Taping

The person responsible for the accuracy and speed of all linear measurements with the tape.

Headtapeman

He determines and directs the marking of points or stations, orders the clearing out of obstructions along lines to be measured, and is the person who carries the zero end of the tape ahead.

Headtapeman

He keeps a record of all measurements, sketches, and observations taken during the process of measurement.

Recorder

He checks by pacing all measurements made by the tapemen for possible errors, mistakes, and blunders.

Recorder

The person whose duty is to hold the range pole (or flagpole) at selected points.

Flagman

He helps the tapemen in making measurements and assists in clearing out obstructions along the line to be measured.

Flagman

The person whose duty is to assist the head tapeman during a taping operation.

Reartapeman

He is the one who holds the 30-meter end or any intermediate meter mark of the tape during a measurement.

Reartapeman

Are calibrated at controlled conditions.

Measuring Tape

They need to consider environmental factors when measuring distances using these instruments.

Surveyors

Is another procedure of obtaining horizontal distances.

Tachymetry

Is based on the optical geometry of the instruments employed and is an indirect method of measurement.

Tachymetry

Is used to determine subtended intervals and angles on a graduated rod or scale from which distances are computed by trigonometry.

Transit

Defined as the horizontal angle the line makes with an established line of reference.

Direction of a Line

Kinds of angles which can be used to describe the direction of lines:

Interior Angles, Deflection Angles, Angles to the Right, Bearings, Azimuth

Are angles between adjacent lines in a closed polygon.

Interior Angles

Are located outside a closed polygon and are referred to as explements of interior angles.

Exterior Angles

Are angles between a line and the prolongation of the preceding line.

Deflection Angles

Are measured clockwise from the preceding line to the succeeding line.

Angles to the Right

The direction of a line may be described by giving its __.

Bearing

The acute horizontal angle between the reference meridian and the line.

Bearing of a Line

Measured clockwise from the north.

Whole-Circle Bearing

The actual angle between the reference meridian (either north or south) and the line.

Reduced Bearing

Are horizontal angles observed clockwise from any reference meridian.

Azimuths

In plane surveying, they are generally observed from the north, but astronomers and the military have used the south as the reference direction.

Azimuths

They used the south as its reference for azimuths for __, but the north has been adopted for __.

National Geodetic Survey (NGS), NAD27, NAD83

For long sights and accurate levelling work, the __ of the earth and __ of the line of sight shall have to be taken into consideration.

Effects of Curvature and Refraction

General term applied to any of the various processes by which elevations of points or differences in elevation are determined.

Levelling

Method for checking and recalibrating a level or transit.

Two-Peg Test

This method is either for an optical or digital level, or a transit being used as a level.

Two-Peg Test

If this error is corrected with a transit, it also improves the accuracy of its vertical angle readings.

Two-Peg Test

Enumeration

Sabrina Mikhaela Canindo · 42問 · 1年前

Enumeration