Land Surveying Concepts Summary

Objectives of Land Surveying

  • Define land surveying

  • Explain the purpose of surveying

  • Differentiate between map and plan

  • Explain two basic principles of surveying

  • Explain functions of a surveyor

  • Identify factors affecting accuracy and precision in measurements

Definition of Surveying

  • Art, science, and technology determining relative positions of points on/beneath the Earth's surface.

  • Achieved through linear and angular measurements.

Purpose of Surveying

  • Determine relative positions of natural and man-made features.

  • Measure relative heights/depths using a reference horizontal plane (datum).

  • Plot measurements for future reference and engineering uses.

Difference between Map and Plan

  • Map: small scale (e.g., 1 m = 100 km)

  • Plan: large scale (e.g., 1 cm = 1 m)

Principles of Surveying

  1. Working from Whole to Part: Establish control points, then subdivide for accuracy.

  2. Fixing a Point in Relation to Two Control Points: Establish new points based on two fixed points.

Who is a Surveyor?

  • Professional with qualifications to measure and represent land and three-dimensional objects.

  • Involves planning, managing land use, and conducting related research.

Measurement and Accuracy Factors

  • Affected by scale, purpose, instrument types, land extent, time, finance, and operator’s errors.

Scale

  • Ratio comparing distances on a map to actual ground distances.

  • Plain scale and representative fraction (RF) noted.

  • Recommended scales vary based on map type.

Survey Classification

  • By Type: Plane vs. Geodetic Surveying

  • By Purpose: Preliminary, Control, Location, Engineering, Hydrographic, Topographic, Geological, Military, Cadastral Surveys.

  • By Instrument: Chain, Compass, Leveling, Theodolite, GPS, etc.

  • By Methods/Phases: Reconnaissance, Preliminary, Control, and Construction Surveys.

Stages of Survey Operations

  1. Field Work: Includes reconnaissance, observations, and field records.

  2. Office Work: Drafting, computing, and organizing field data.

  3. Care of Instruments: Proper maintenance and handling of survey equipment.

Errors in Measurements

  • Categories: Natural, Instrumental, Personal

  • Types: Gross Errors, Systematic Errors, Random Errors

Surveying is the profession involved in the analysis and measurement of land and the arrangement of boundaries, using various techniques and technologies to establish precise locations of points and features on the Earth's surface for construction, mapping, and land management purposes.