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GE 100 – General Surveying 1 1  GE 100 – GENERAL SURVEYING I Course Overview No. of Units: 4 units ( 2 units Lecture, 2 units Laboratory) Total Contact Hours: 36 hours Lecture, 108 hours Laboratory Pre-requisite: None Co-requisite: None Course Description: Plane surveying mea...

GE 100 – General Surveying 1 1  GE 100 – GENERAL SURVEYING I Course Overview No. of Units: 4 units ( 2 units Lecture, 2 units Laboratory) Total Contact Hours: 36 hours Lecture, 108 hours Laboratory Pre-requisite: None Co-requisite: None Course Description: Plane surveying measurements and error theory; horizontal and vertical distance measurements; use of principal surveying instruments; basic plane surveying operations and computational method of position, traverses, and areas; basic cartography. Course Intended Learning Outcomes (CILOs) After completion of the course, the student must be able to: 1. Explain the principles and applications of plane surveying and the use of surveying instruments. 2. Execute plane surveys following established guidelines, specifications, and standards of accuracy. 3. Solve horizontal and vertical distances, traverses, areas, and subdivision problems. 4. Prepare maps and survey plans following cartographic standards. GE 100 – General Surveying 1 2  LECTURE NO. 1 – INTRODUCTION TO SURVEYING NO. OF HOURS: 2 hours TOPIC INTENDED LEARNING OUTCOME At the end of the lecture, the students would be able to: Define Geomatics as a broad field of gathering, storing, processing, and delivering geographic information or spatially referenced information. Differentiate Geodetic Engineering from Geomatics. Differentiate the various disciplines of Geomatics, which include surveying and mapping, among others. Explain the history, major concepts, and principles of surveying. Differentiate plane surveying from geodetic surveying. Identify the different uses and types of surveys. TEACHING/LEARNING STRATEGIES Lecture/ Discussion using Slide Presentation Demonstration Lecture Illustrated Presentation Brainstorming Peer Teaching REQUIRED COURSE MATERIALS Reference Textbook DAO No. 98-12 (Revised Manual of Land Surveying Regulations in the Philippines) Research materials from the internet Laptop Projector Whiteboard and Marker CONTENT Definitions of Geodetic Engineering, Surveying and Geomatics Concepts and Principles of Surveying and Geomatics History of Surveying Uses, Classification, and Types of Surveys GE 100 – General Surveying 1 3 DEFINITIONS OF GEODETIC ENGINEERING, SURVEYING, AND GEOMATICS Based on CMO No. 89, series of 2017, the definition of Geodetic Engineering is a branch of engineering which deals with the collection and measurement of spatial data above, on, or below the surface of the earth using appropriate technologies and the scientific and methodological processing and management of these data for the production of spatial information systems, maps, plans, charts, and other documents. Through its definition, it deals with the collection and measurement of spatial data or information which is also known as geospatial data or geographic information. It is the data or information that identifies the geographic location features and boundaries on Earth such as natural or constructed features, oceans, and more. It is usually stored as coordinates and is data that can be mapped. The word “spatial” means the location of the information is known in three dimensional (3D) space (i.e. x,y,z). It is often accessed, manipulated, or analyzed through GIS as shown in Figure 1. Figure 1. Spatial Data Information through GIS CONCEPTS AND PRINCIPLES OF GEOMATICS According to the Dept. of Surveying and Spatial Information Science, Univ. of Tasmania, Geomatics Engineering is the science concerned with the measurement, representation, analysis, management, retrieval, and display of spatial information describing both the Earth’s physical features and built-in environment. It is also considered as applied science and professional discipline. In applied science, it involves an integrated approach to the measurement, analysis, management, and display of geographic and other spatial data. As a professional discipline, Geomaticians have GE 100 – General Surveying 1 4 specialist skills, knowledge, and understanding to provide services that meet the needs of society and which contribute to social and political stability, quality of life, and the management of natural heritage and resources. Figure 2 shows the five (5) disciplines of Geomatics. Figure 2. Discipline of Geomatics HISTORY OF SURVEYING The oldest historical records in existence today that bear directly on the subject of surveying state that this science began in Egypt. Herodotus recorded that Sesostris (about 1400 B.C.) divided the land of Egypt into plots for taxation. Annual floods of the Nile River swept away portions of these plots and surveyors were appointed to replace the boundaries. These early surveyors were called rope-stretchers since their measurements were made with ropes having markers at unit distance Heron of Alexandria (Figure 3), the Great-Great Grandfather of Engineering, is one of the most intelligent innovators ever. He stands out prominently for applying science to surveying in about 120 B.C. He was the author of several important treatises of interest to surveyors, including the Dioptra (Figure 4), which related the methods of surveying a field, drawing a plan, and making related calculations. It is also described as one of the first pieces of equipment recorded. A dioptra is a classical astronomical and surveying instrument. It was a Figure 3. Heron of sighting tube or a rod with a sight at both ends, attached to a stand Alexandria and if fitted with protractors, it could be used to measure angles. For GE 100 – General Surveying 1 5  many years Heron’s work was the most authoritative among Greek and Egyptian surveyors. Figure 4. Dioptra Shape and Size of the Earth In the early civilizations, determining the true shape and size of the Earth has intrigued humans for centuries. The Earth is assumed to be a flat surface. But by noting the Earth’s circular shadow on the moon during the lunar eclipses and watching the ships gradually disappear as they sailed toward the horizon, it was slowly deduced that the planet curved in all directions. A Greek named Eratosthenes (Figure 5) was among the first to compute the Earth’s dimension. His procedure occurred at around 200 B.C. He had observed that on the day of the summer solstice, the midday sun shone to the bottom of a well in the town of Syene (Aswan) as shown in Figure 6. At the same time, he observed the sun was not directly overhead at Alexandria; instead, it cast a shadow with the vertical equal to 1/50th of a circle (7° 12'). To these observations, Eratosthenes applied certain "known" facts that (1) on the day of the summer solstice, the midday sun was directly over the line of the summer Tropic Zone (Tropic of Cancer)-Syene was therefore Figure 5. Eratosthenes concluded to be on this line; (2) the linear distance between GE 100 – General Surveying 1 6 Alexandria and Syene was 500 miles; (3) Alexandria and Syene lay on a direct north-south line. Figure 6. Eratosthenes Observation in Alexandria and Syene From these observations and "known" facts, Eratosthenes concluded that since the angular deviation of the sun from the vertical at Alexandria was also the angle of the subtended arc, the linear distance between Alexandria and Syene was 1/50 of the circumference of the earth or 50 x 500 = 25,000 miles.. DEFINITION OF SURVEYING, USES, CLASSIFICATION, AND TYPES OF SURVEYS Definition of Surveying All surveying operations have the same basic characteristics that of delineating a portion of the Earth’s surface of establishing the boundaries of some object upon it. A host of definitions have been made as follows: Surveying is a branch of applied mathematics that is concerned with determining the area of any portion of the earth’s surface, the lengths and directions of the bounding lines, and the contour of the surface and with accurately delineating the whole paper – Merriam Webster. GE 100 – General Surveying 1 7  Surveying is 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 - Ghilani and Wolf. From the definitions given above, it is observed that surveying activities during the earlier part of the decade have only been limited to surveys on or near the surface of the earth. However, times have changed and the modern surveying techniques are now applied to space exploration and in the mapping of extraterrestrial bodies. The author believes that the science of surveying is now much wider and complex in extent and that it should be redefined appropriately as surveying is the art and 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 applied mathematics and the use of specialized equipment and techniques. Uses of Surveys Through time, the use of surveying expanded in engineering construction, planning, and design. Surveys also cover a wide range in scope and complexity such as staking out of simple structures, surveying of small parcels of land and extensive and difficult surveys required in the construction of subdivisions, bridges, highways, canals, dams, railroads, wharves, missile and rocket launching sites, drainage and irrigation systems and surveys of relatively large portions of the earth’s surface. Classification of Surveys Surveys are divided into two general classifications, plane and geodetic. 1. Plane Surveying It is a type of surveying in which the earth is considered to be a flat surface, and where distances and areas involved are of the limited extent that the exact shape of the earth is disregarded. 2. Geodetic Surveying ▪ They are surveys of a wide extent which take into account the spheroidal shape of the earth. Types of Surveys Of the different types of surveys, the following are the more commonly executed: GE 100 – General Surveying 1 8 1. Cadastral surveys are usually closed surveys that are undertaken in urban and rural locations to determine and define property lines and boundaries, corners, and areas. 2. City surveys are conducted of the areas in and near a city to plan expansions or improvements, locate property lines, fixing reference monuments, determining the physical features and configuration of the land, and preparing maps. 3. Construction surveys are undertaken at a 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. 4. Forestry surveys are executed in connection with forest management and mensuration, and the production and conservation of forest land. 5. Hydrographic surveys refer to surveying streams, lakes, reservoirs, harbors, oceans, and other bodies of water. 6. Industrial surveys are sometimes known as optical tooling and it refers to the use of surveying techniques in shipbuilding, construction, and assembly of aircraft, layout, and installation of heavy and complex machinery, and other industries where very accurate dimensional layouts are required. 7. Mine surveys are performed to determine the position of all underground excavations and surface mine structures, to fix surface boundaries of mining claims, determine geological formations, to calculate excavated volumes, and establish lines and grades for other related mining work. 8. Photogrammetric surveys are the type of survey which makes use of photographs taken with specially designed cameras either from airplanes or ground stations. 9. Route surveys involve the determination of alignment, grade, earthwork quantities, 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. 10. Topographic surveys are made for determining the shape of the ground, and the location and elevation of natural and artificial features. GE 100 – General Surveying 1 9