According to Ghilani, C. & Wolf, P. (2012) Land Surveying, which has recently also been interchangeably called Geomatics has traditionally been defined as the science, art, and technology of determining the relative positions of points above, on, or beneath the Earth’s surface, or of establishing such points. In a more general sense, however, surveying (geomatics) can be regarded as that discipline which encompasses all methods for measuring and collecting information about the physical earth and our environment, processing that information, and disseminating a variety of resulting products to a wide range of clients.
A Land Surveyor
A land surveyor is a professional person with the academic qualifications and technical expertise to conduct one, or more, of the following activities;
· to determine, measure and represent the land, three−dimensional objects,point−fields, and trajectories;
· to assemble and interpret land and geographically related information;
· to use that information for the planning and efficient administration of the land, the sea and any structures thereon
· to conduct research into the above practices and to develop them. (FIG)
The Land surveyor’s professional tasks may involve one or more of the following activities, which may occur either on, above, or below the surface of the land or the sea and may be carried out in association with other professionals.
1. The determination of the size and shape of the earth and the measurements of all data needed to define the size, position, shape and contour of any part of the earth and monitoring any change therein.
2. The positioning of objects in space and time as well as the positioning and monitoring of physical features, structures and engineering works on, above or below the surface of the earth.
3. The development, testing and calibration of sensors, instruments and systems for the above−mentioned purposes and for other surveying purposes.
4. The acquisition and use of spatial information from close range, aerial and satellite imagery and the automation of these processes.
5. The determination of the position of the boundaries of public or private land, including national and international boundaries, and the registration of those lands with the appropriate authorities.
6. The design, establishment and administration of geographic information systems (GIS) and the collection, storage, analysis, management, display and dissemination of data.
7. The analysis, interpretation and integration of spatial objects and phenomena in GIS, including the visualization and communication of such data in maps, models and mobile digital devices.
8. The study of the natural and social environment, the measurement of land and marine resources and the use of such data in the planning of development in urban, rural and regional areas.
9. The planning, development and redevelopment of property, whether urban or rural and whether land or buildings.
10. The assessment of value and the management of property, whether urban or rural and whether land or buildings.
11. The planning, measurement and management of construction works, including the estimation of costs.
Land Surveying is primarily classified as under:
1. Plane Surveying is that type of surveying in which the mean surface of the earth is considered as a plane and the spheroidal shape is neglected. All triangles formed by survey lines are considered plane triangles. The level line is considered straight and all plumb lines are considered parallel.
2. Geodetic Surveying is that type of surveying in which the shape of the earth is taken into account. All lines lying in the surface are curved lines and the triangles are spherical triangles. It therefore, involves spherical trigonometry. All Geodetic surveys include work of larger magnitude and high degree of precision. The object of geodetic survey is to determine the precise position on the surface of the earth, of a system of widely distant points which form control stations to which surveys of less precision may be referred.
Specialized Types of Land Surveys
Engineering surveying is defined as those activities involved in the planning and execution of surveys for the location, design, construction, operation and maintenance of civil and other: engineering projects. The surveying activities are:
i. Preparation of surveys and related mapping specifications;
ii. Execution of photogrammetric and field surveys for the collection of required data including topographic and hydrographic data;
iii. Calculation, .reduction and plotting cf survey data for use in engineering design;
iv. Design and provision of horizontal and vertical control survey networks;
v. Provision of line and grade and other layout work for construction and mining activities;
vi. Alignment of linear engineering projects.
Control surveys establish a network of horizontal and vertical monuments that serve as a reference framework for initiating other surveys.
Topographic surveys determine locations of natural and artificial features and elevations used in map making.
Cadastral surveys establish property lines and property corner markers, it is the surveys of the public lands systems
Hydrographic surveys define shorelines and depths of lakes, streams, oceans, reservoirs, and other bodies of water. Sea surveying is associated with port and offshore industries and the marine environment, including measurements and marine investigations made by shipborne personnel. Hydrographic also plays an important role in preparation of navigational information for shipping as well as exploration of marine resources.
Mine surveys are performed above and below ground to guide tunneling and other operations associated with mining. This classification also includes geophysical surveys for mineral and energy resource exploration.
The science and the technology which develops and uses information science infrastructure to address the problems of geography, cartography, geosciences, locations and related branches of science and engineering.
This is the kind of survey of collecting aerial data (digital aerial imagery) by using Aero planes, helicopters, UAVs (drones), balloons and etc. Normally data collected are aerial photography, LiDAR and also geophysical data such as aeromagnetic surveys and gravity. Aerial survey should
be distinguished from satellite imagery technologies because of its better resolution, quality and atmospheric conditions. Nowadays, aerial survey is sometimes recognized as a synonym for aerophotogrammetry, part of photogrammetry where the camera is placed in the air. All Measurements on aerial images are provided by photogrammetric technologies and methods.
GPS Satellite Surveying and Satellite Imagery
Surveyors use Global Positioning Systems (GPS) in all kinds of surveying. Satellite imagery is also being used to monitor movements on the earth’s surface –earth quake zones, potential mud slides or even troops on the move in a war zone.
Geographic Information Systems
Geographic Information Systems is simply a computer−based tool that analyzes stores, manipulates and visualizes geographic information on a map. The use of GIS is needed to collect data, store, manage, analyze and produce useful information. A land surveyor use the high accurate GPS, Mobile GIS device and total stations to collect data from site and analyze them to meet the needsof the community or the environment.