Surveying Definitions and Classifications

Surveying Definitions and Classifications

• Surveying is the art and science of determining the relative positions of points on the Earth's surface.
• Primary classifications are plane surveying and geodetic surveying, distinct in their approach to Earth's curvature. Plane surveying assumes a flat Earth and is appropriate for smaller areas. Geodetic surveying accounts for Earth's spheroidal shape, used for larger areas.
• Various survey types exist, including cadastral, topographic, hydrographic, construction, and as-built/final surveys. Each type has associated applications.

Survey Types and Applications

• Cadastral/Legal Surveys: Focus on property boundaries, including perimeter, boundary identification, and investigation.
• Topographical Surveys: Map features of the terrain, such as elevation.
• Hydrographical Surveys: Study water bodies.
• Construction/Layout Surveys: Guide construction projects.
• As-Built/Final Surveys: Document completed projects.
• Surveying is used to create topographic, cadastral, and engineering maps; and military maps and reconnaissance.

Surveying Instruments and Equipment

• Instruments and equipment like total stations, GPS, theodolites, steel tapes, fiberglass tapes, levels, and levelling rods are essential for surveying.
• Understanding instrument care and safety procedures is vital.

Techniques and Errors

• Taping techniques and resulting errors are significant aspects of surveying.
• Measuring slopes and errors in pacing measurements are key.
• Advantages and disadvantages of steel tapes and fiberglass tapes must be understood.
• Components of a GPS system (space, control, and receiver components) are key concepts.
• Factors influencing route surveys, including environmental and social impact as well as considerations about terrain, must be assessed.
• Total stations, optical theodolites, and GPS strengths and limitations are crucial knowledge.
• Fundamental principles of surveying, like surveying planning, efficiency and accuracy checking, are pivotal.

History and Units

• Surveying history, from historical tools to modern equipment, should be understood.
• Knowledge of metric and imperial units of measurement is required in all surveying processes.
• Surveying equipment and accessories, including total stations, theodolites, automatic levels, and GPS equipment, are needed to complete all surveys.

Accuracy and Precision

• Understanding accuracy and precision in surveying is important.
• Knowing the different errors in surveying is important, like random errors, systematic errors, and blunders.

Levelling

• Levelling's definition and procedures for setting up and operating levels and levelling rods are essential.
• Associated terminology (backsight, foresight, intermediate sight, datum, reduced level, height of instrument, benchmark, elevation) are critical.
• Applications of levelling include topographic mapping, determining elevations, and calculating volumes.
• Various levelling techniques (simple levelling, differential levelling, total station techniques, and GPS techniques) are crucial.
• Levelling equipment (automatic levels, digital levels, levelling rods) and their associated accessories should be understood.
• Two-peg test procedures, including field procedures and computation using rise and fall methods are necessary.
• Understanding the role of survey departments and planning authorities in subdivision approval processes is essential.
• Calculations associated with reduced level computation using the rise and fall method.