Arch 3124: Surveying Fundamentals

• Surveying is introduced as a topic within the Arch 3124 course, covering definitions, the necessity for surveying, classifications, measurement units, error theory, accuracy, error origins, and descriptive term definitions.

Learning Outcomes

• Students should understand surveying history.
• Students should be able to define surveying and describe its importance.
• Students should identify and classify surveying types.
• Students should understand and use measurement units.
• Students should identify and classify error sources.
• Students should know terms for describing errors.

Surveying History

• It began when people settled, needing to manage land and domesticate animals for agriculture.
• Agriculture led to conserved land ownership.
• Armies protected city/state borders.
• The art of surveying is an old and vital practice for marking boundaries and dividing land.

Definition of Surveying

• Surveying is the art and science of determining relative positions of natural and artificial features on, above, or below the Earth's surface, presenting this information graphically or numerically.
• A combination of art and science helps surveyors find optimal solutions for surveying challenges.
• Science uses mathematical techniques to ensure data accuracy and reliability, grounded in scientific measurement principles.
• Relative positions relate the location of points to another object/reference point/station.
• AASTU is 3 km North-east of Akaki Town, illustrating a location (relative position) described relative to Akaki Town.

Engineering Surveying

• It involves planning and executing surveys for the location, design, construction, maintenance and operation of civil, architectural, and other engineered projects.
• It includes methods for measuring, processing, and sharing information about the physical world.

Why Surveying Is Needed

• It supports modern life by mapping the Earth above and below sea level.
• It creates navigational charts for air, land, and sea travel and establishes the boundaries of private and public lands and aids land management.
• It helps determine the size, shape, gravity, and magnetic fields and creates charts of the moon and planets.

Surveying's Role

• It is essential for the planning, design, layout, and construction of infrastructure and the physical environment.
• It links design and construction and is used in construction, land-use projects, and modern industrial technologies.
• Key tasks include fixing national/state boundaries, creating control points, collecting field data, and creating plans/maps for engineering projects.
• It helps compute boundaries, areas, and volumes alongside analyzing field parameters for setting out actual engineering works.

The two fundamental reasons for surveying include

• Determining the location of existing objects on or near the Earth's surface and laying out or locating new points/objects for construction.

Surveying Activities During Construction

• The steps include planning, data collection, and field observations.
• Data processing, map/plan creation, numerical data provision, setting-out, field checks, data services, final plans, documentation, and deformation monitoring.

Principles of Surveying

• Classification differs based on shape of the earth, purpose, instruments, and nature.
• The shape is an oblate spheroid, bulging at the equator. The Earth is categorized based on whether curvature is considered.

Types of Surveying

• Plane surveying does not consider Earth's curvature, assuming a flat surface.
• Distances and angles project onto a horizontal plane, suited for small areas.
• Geodetic surveying accounts for Earth's curvature, determining precise positions of widely spaced points on the Earth's surface.
• Geodesy measures and represents the Earth, including its gravity field in 3D-time varying space.

Instruments

• Common types of equipment used categorized based on their need and dependence on light.
• Pre-light instruments include tapes, chains, and compasses.
• Light-based instruments are plane tables, transits, levels, theodolites, and photogrammetry equipment.
• Electronic instruments includes EDM and total stations.
• Remote sensing relies on GPS and satellite images.

Instrument-Specific Surveys:

• Chain surveys use only linear measurements.
• Traverse surveys use both linear and angular measurements.
• Triangulation surveys use triangle networks for larger areas, with precise measurement of one side.
• Tacheometric surveys use transit telescopes to measure horizontal and vertical distances.
• Plane table, total station, leveling, theodolite, and compass surveys measure data.
• Satellite surveys use GPS for land/sea/space information.

Surveying Purposes

• Route surveys establish positions for highways, railways, and utility lines.
• Property surveys determine boundaries and property corners, used for land subdivisions and establishing ownership.
• Control surveys provide horizontal/vertical position data as a reference.
• Topographic surveys collect data for maps showing terrain and features.
• Construction surveys mark positions of new elements on the ground.
• Setting out transfers designs onto the land for construction.
• Boundary surveys establish property corners and land parcel areas.
• City surveys involve town developments.
• Hydrographic surveys map water bodies.
• Other types include mine, astronomic, satellite, geological, and engineering surveys.

Classified Based on Observation Point

• Ground/terrestrial, hydrographic, underground, and aerial/photogrammetric methods are all various types of surveying based on where gathering of data happens.
• Land, marine/hydrographic, and underground surveys are also methods of categorizing surveys based on the environment they're focused on.

Instruments

• Underground constructs tunnels while aerial ones collect photos which each are practical for different scales of projects.

Equipment Care

• Expected precise and accurate results rely on having the best equipment.
• Prioritize handling, stowing, and maintenance of the equipment.
• Survey equipment is used for various construction applications from surveys to heavy engineering and precision manufacturing, these are costly.
• Contractors maintain these instruments properly by being cautions of the environmental effect on the instruments.
• Ensure regular serving, calibration, and software updates.
• Always store the equipment in its case and cleaning it, while observing job site conditions and warning signs.

Proper Upkeep

• In order to keep everything in the best optimal condition avoid dust, head and moisture.

Surveying Phases

• Office phase includes planning, data adjustments, and plan creation.
• Fieldwork consists of reconnaissance, instrument handling, measurements, setting out, and data recording.
• Success depends on project knowledge, and is performed through desk study, research, analysis, data acquisition, computing, mapping, monument placement, and reporting.

Good Field Notes

• Good field notes and proper structure make way for less confusion by providing figures, remarks, sketches, and valuable documents recording the time and expenses involved in obtaining such data.
• They need to have, accuracy, integrity, legibility, arrangement, and clarity.

Measurement Types

• Common survey measurements include horizontal/vertical distances, slope distance, and horizontal/vertical angles.
• Horizontal distance: linear measurement on the horizontal plane.
• Vertical distance: height difference along the vertical axis.
• Slope distance: shortest distance from instrument to target.
• Horizontal angle: measured on the horizontal plane to establish azimuth.
• Vertical angle: measured in the vertical plane.

Units of Measurement

• Measurement compares unknowns with standards and estimates quantity magnitude.
• Measurement error is the difference between measured and true value and units quantify physical quantities following convention.
• There are two systems: MKS (metric) and FPS (British).
• Angular measurements use sexagesimal (degrees), centesimal (gons), or radian systems.

Unit Conversion

• Converting between units or systems requires knowing conversion factors.
• The SI base unit of length is the meter (m), with multiples and submultiples ranging from decameter to picometer.
• The SI unit for area is the square meter (m²).
• The SI unit for volume is the cubic meter (m³).
• Conversions exist for length, area, volume, and angles, as well as length.

Map Scale

• It's the ratio of map distance to ground distance.
• It helps users convert between distance son the map and on the ground.
• There are large/medium/small scales, where large scales display features bigger than small scales, with denominators indicating scale, such as 1:1,000 (large) to 1:50,000 (small).
• A map's scale is verbally represented, as a representative fraction, or graphically.
• Verbal scales use familiar terms.
• Representative fractions express the scale as a ratio, independent of units.
• Graphical scales use a ruler printed on the map.

Errors in Surveying

• Imperfections in measurements are inevitable.
• The true value and exact error sizes remain unknown with surveying to minimize measurement mistakes.
• Known sources pave the way for error type identification, effect analysis, result analysis, and precision and accuracy in degree.
• Mistakes are gross errors needing careful observation and booking, while systematic errors are constant and correctable.
• Random errors result from irregular causes and compensate over numerous measures.
• Accuracy reflects nearness to the true value against precision which gauges consistency of data against instrument refinement.
• Influences include the person taking care to be precise when making the measurement as well as instrument, number of times measurements were taken and the amount of care used when making the measurement.
• Errors arise from natural or instrumental conditions, and personal mistakes.
• High accuracy needs blunder elimination, fixed systematic errors, and minimized random errors.
• Accuracy measures how measured values reflect true values.
• The degree of accuracy reflects error ratio to measured quantity.
• A unit error over 10,000 units shows accuracy, and precision is key.
• Surveying blends nature with methods for consistency within limits thanks to high standards.