Surveying (Midterms) Flashcards
terms and concepts
It is the art of 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 bodies through applied mathematics and the use of of specialized equipment and techniques
Surveying
Two General Classification of Surveys
Plane Surveying and Geodetic Surveying
The earth is considered to be a flat surface
Plane Surveying
The curvature of the Earth is not taken into consideration
Plane Surveying
Suitable for small-area surveying
Plane Surveying
Survey accuracy is low
Plane Surveying
Economic and easy survey method
Plane Surveying
Takes into the account the spheroidal shape of the Earth
Geodetic Surveying
The curvature of the Earth is taken into consideration.
Geodetic Surveying
Suitable for large area
Geodetic Surveying
Survey accuracy is high
Geodetic Surveying
Special instrument needed and long survey method
Geodetic Surveying
Types of Surveys
Cadastral Survey
City Survey
Construction Survey
Forestry Survey
Hydrographic Survey
Industrial Survey
Mine Survey
Photogrammetric Survey
Route Survey
Topographic Survey
Closed surveys in urban and rural locations to determine and define property lines and boundaries, corners, and areas.
Cadastral Surveys
Are surveys of the areas in and near a city to plan expansions or improvements, locate property lines, fix reference monuments, determine the physical features and configuration of the land, and prepare maps.
City Surveys
Undertaken at construction site to provide data regarding grades, reference lines, dimensions, ground configuration, and the location and elevation of structures which are of concern to engineers, architects, and builders.
Construction Surveys
Survey in connection with forest management and mensuration, and the production and conservation of forest lands.
Forestry Surveys
Surveys made to map shorelines, chart the shape of areas underlying water surfaces, and measure the flow of streams.
Hydrographic Surveys
Use of surveying techniques in shipbuilding, construction and assembly of aircraft, layout, and installation of heavy and complex machinery, and in other industries requiring very accurate dimension layouts.
Industrial Surveys
Determines the position of all underground excavations and surface mine structures, to fix surface boundaries of mining claims, determines geological formations, calculates excavated volumes, and establishes lines and grades for other related mining work.
Mine Surveys
Survey which uses photographs taken with specially designed cameras either from airplanes or ground stations.
Photogrammetric Surveys
Involves the determination of alignment, grades, earthwork quantities, and 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.
Route Surveys
Surveys to determine the shape of the ground, the location and elevation of natural and artificial features upon it.
Topographic Surveys
Two types of Measurements
Direct Measurements and Indirect Measurements
Comparison of the measured quantity with a standard measuring unit (makes use of instruments to measure the quantity)
Direct measurements
Made when it is not possible to apply a measuring instrument directly to a quantity.
Indirect measurements
SI unit for plane angles
Radians
the angle subtended by an arc of a circle having a length equal to the radius of a circle
plane angles
the degree, minute, second
sexagesimal units
uses grads (360° = 400 grads)
centesimal units
Types of Notes
Sketches
Tabulations
Explanatory
Computations
Combinations of the above
Information found in Field Notebooks
Title of the Fieldwork / Project Name
Time of the Day and Date
Weather Conditions
Name of Group Members and their designations
List of Equipment
Person who is responsible for the overall direction, supervision and operational control of the survey party. Responsible for submitting survey reports and records, and sees to it that these are complete, accurate and adheres to prescribed technical standards and specifications.
Chief of Party
Person whose duty is to assist the chief of party in the accomplishment of the task assigned to the survey party. Conducts ground reconnaissance and investigates sites of a proposed project to gather necessary data prior the employment of surveying equipment, instruments and accessories used in the survey operation. Prepares field and office reports and survey plans for submission to chief of party.
Assistant of Chief of Party
Person whose duty is to set up, level, and operate surveying instruments. Sees to it that instruments to be used are in good working condition and in proper adjustment.
Instrument Man
Person who is responsible for use and operation of all electronic instruments required in a field work operation. It is the duty of the technician to see to it that these equipment are functioning properly, are regularly calibrated, and are in proper adjustment. Responsible for the establishment of a two-way communication link by radio between members of the survey party and the office , and between members of the survey party where distant stations or long survey lines are involved.
Technician
Person whose duty is to perform all computations of survey data and works out necessary computational checks required in a field work operation.
Computer
Person whose duty is to keep a record of all sketches, drawings, measurements and observations taken or needed for a field work operation.
Recorder
Person responsible for accuracy and speed of all linear measurements with tape. Determines and directs the marking of stations to be occupied by instruments and directs clearing of obstruction along the line of sight. Responsible for eliminating or reducing possible errors and mistakes in taping.
Head Tape Man
Person whose duty is to assist the head tapeman during taping operations and in other related work
Rear Tape Man
Person whose duty is to hold the flagpole or range pole at selected points as directed by the instrument man. Where electronic distance measuring instruments are used, he is responsible for setting up reflectors or targets.
Flag Man
Person who holds the stadia or leveling rod when sights are to be taken on it.
Rod Man
Person whose duty is to clear the line of sight. Responsible also for the safety and security of members of the survey party at the survey site.
Axeman / Lineman
Person whose duty is to render first aid treatment to members of the survey party who are involved in accidents involving their health, safety, and well-being.
Aidman
Person whose duties are to render other forms of assistance needed by the survey party or as directed by the chief of party.
Utility Man
Type of Errors
Systematic Errors and Accidental Errors
This type of error is one which will always have the same sign and magnitude as long as field conditions remain constant and unchanged.
Systematic Errors
These errors are purely accidental in character. The occurrence of such errors are matters of chance as they are likely to be positive or negative, and may tend in part to compensate or average out according to laws of probability.
Accidental Errors
Source of Errors
Instrumental Errors
Natural Errors
Personal Errors
Due to imperfections of the instrument used.
Instrumental Errors
Caused by variations in the phenomena of nature.
Natural Errors
Arise from the limitations of the senses of sight, touch and hearing of the human observer which are likely to be erroneous or inaccurate.
Personal Errors
refers to the degree of refinement or consistency of a group of observations and is evaluated based on discrepancy size.
Precision
denotes the absolute nearness of observed quantities to their true values
Accuracy
one of the simplest methods of measuring distances. It is used in instances where approximate results can be enough for the data needed, such as getting the rodman in position during a cross-section survey, or simply measuring a relatively short distance where accuracy is not that of an issue.
Pacing
Length of a step (Measured heel-to-heel or toe-to-toe)
Pace
A double step (One stride is equivalent to two paces)
Stride
Distance covered by one pace.
Pace Factor
Factors Affecting Length of Pace
Speed of Pacing
Roughness of the Ground
Weight of clothing and shoes used
Fatigue on the part of the pacer
Slope of the terrain
Age and sex of the individual
Mechanical Pace Counter
Pedometer
Passometer
Hands and hips body movement
Pedometer
Body movement and velocity
Passometer
Use of a graduated tape is the most common method of measuring horizontal distances.
Taping
measurement of distances using chains
Chaining
persons undertaking measurement using chains
Chainmen
Taping Accessories
Plumb-Bob
Pegs
Chalk
Steel Tape
Tripod
Ranging Rod
6 Steps: Taping on Level Ground Using Tape
Lining in
Applying Tension
Plumbing
Marketing Tape Length
Recording
Recording Distance
Number of times something will probably occur over the range of possible occurences
Probability
refers to a quantity which, based on available data, has more chance of being correct than has any other
Most probable value
it means that the probability of true error being less or greater than the probable error is 50%
probable error
This type of error is one which will always have the same sign and magnitude as long as field conditions remain constant and unchanged.
systematic errors
These errors are purely accidental in character. The occurrence of such errors are matters of chance as they are likely to be positive or negative, and may tend in part to compensate or average out according to laws of probability.
accidental error
A line that follows the local direction of gravity as indicated by a plumb line
vertical line
A curved surface that at every point is perpendicular to the local plumb line (the direction in which gravity acts).
level surface
The distance measured along a vertical line from a vertical datum to a point or object
elevation
A relatively permanent object, natural or artificial, having a marked point whose elevation above or below a reference datum is known or assumed.
bench mark
Intervening point between two bench marks upon which point foresight and backsight rod readings are taken
turning point
Units of Measurements
Linear, Area, and Volume Measurements
Angular Measurements
The Field Survey Party
Chief of Party
Assistant Chief of Party
Instrument Man
Computer
Recorder
Head Tapeman
Rear Tapeman
Flagman
Rodman
Pacer
Axeman / Lineman
Aidman
Utilityman
is another procedure of obtaining horizontal distances
tachymetry
this method provides a rapid mass of determining horizontal distances
stadia method
it is an acronym for geodetic distance meter
geodimeter
is the process of directly or indirectly measuring vertical distances to determine the elevation of points or their differences in elevation
level
it is curved surface which is at any point perpendicular to the direction of gravity or the plumb line
level surface
is a curved line in a level surface all points of which are normal to the direction of gravity and equidistant from the center of the earth
level line
it is a plane that is tangent to a level surface at a particular point
horizontal surface
a straight line in a horizontal plane which is tangent to a level line at one point
horizontal line
this line is perpendicular to the direction of gravity athe point of tangency
horizontal line
is a line parallel to the direction of gravity
vertical line
is an imaginary surface of the sea which is midway between high and low tides
mean sea level
is any convenient level surface coincident or parallel with mean sea level to which elevations of a particular area are referred
datum
is the vertical distance above or below mean sea level of any other selected datum
elevation
is the vertical distance between the to level surfaces in which the points lie
difference in elevation
is the commonly employed method of determining the elevation of points some distance apart by a series of setups of a leveling instrument along a selected route
direct or spirit leveling
is the process of accurately determining the difference in elevation between two intervisible points located at a considerable distance apart and between which points leveling could not be performed in the usual manner
reciprocal leveling
this method of leveling is used to determine differences in elevation between points at designated short-measured intervals along an established line to provide data which a vertical section of the ground surface can be plotted
profile leveling
this method of leveling is employed in determining by trigonometric computations the difference in elevation between two points from measurements of its horizontal or slope distance and the vertical angle between the points
trigonometric leveling
combines features of direct leveling with those trigonometric leveling
stadia leveling
involves the determination of difference in elevation between points by measuring the variation in atmospheric pressure at each pint by means of barometer
barometric leveling
in highway or railroad construction it is often necessary to obtain a representation of the ground surface on either side of the centerline
cross-section leveling
is a method of determining the relative elevations of points in borrow pit excavations for the purpose of calculating volumes of earthwork
borrow-pit leveling
it is a fixed line of reference parallel to the central meridian of a system of plane rectangular coordinates
grid meridian
a level surface that serves as a datum for all elevations and astronomical observations
geoid
a unit for angular measurements in which the circumference is divided into 6400 parts
mils
expedient methods of establishing meridians
Establishing Magnetic Meridian by Compass
Determining True North by Aid of Sun and a Plumb Line
Determining True North by the Rising and Setting of the Sun
Determining True North by Polaris
Determining True South by the Southern Cross
Determining Direction of True North or South by a Wrist watch
