Land Surveying Techniques - Coursework Example

Running Header: Land Surveying Techniques Student’s Name: Instructor’s Name: Course Code & Name: Date of Submission: Land Surveying Techniques Surveying is the process of gathering and gathering the information about the physical earth (Trimpered, 2009, p. 105). It is the science through which relative positions of the already existing points are established. The methods of survey range from simple use of conventional ground methods to the advanced systems like the aerial and the satellite systems. A variety of methods are then used to produce maps which are easy to use. Overall this helps in land management, by helping us to locate boundaries, structures, water courses, roads and any other physical characteristics of the land. The land measurement and survey do relate to many areas. The knowledge of how the land is measured is very necessary part of planning and implementing the various land management techniques. This essay looks at the land surveying techniques and how they contrast with the aspect of topographic mapping and site engineering. The techniques that are used in land surveying are dependent on the type of the survey that is being conducted. There are three major types of survey; land survey, engineering survey and the information survey. The land survey is used to fix the property lines, calculate the areas of the land as well as assist in the transfer of the real property from one person to the other. The engineering survey on the other hand is used to collect the data that is needed for planning and designing of the engineering projects. The information that is collected does ensure that the necessary dimension and the position control on the site are effective so that the structures are built and designed in the proper places. In general there are five techniques used in land surveying. These are triangulation, trilateration, traverse, leveling and radiation. Trilateration is the use of equipments that uses electronic principles to directly measure triangular side lengths. From this data, the angles of the triangles can be calculated(Dallas, Antonio, & Christi 2002 ). In this process, the relative or absolute locations of a specific place are determined using the principles of geometry that relates to triangles, spheres and circles. With regard to measuring distances on the earth service, three satellites, each at a different location would form an intersecting sphere on a point on the earth service. Additional information can be got if the elevation of the satellite is known. This method is quite useful in areas where the positions are rough and one wants to get the exact position of a given point. In contrast to trilateration, triangulation involves the measurement of the angles (Dallas, Antonio, & Christi 2002 ). Triangulation is the means of finding the location of a given point on the land by way of measuring the angles to that point on the either ends of the baseline. In this case, the distances are not measured directly as in the case of trilateration. In surveying, this technique is made possible by the use of the global positioning system. The global positioning system comprises of a network of 24 satellites that orbits the earth while they transmit precise position and time data either night or day and in any kind of weather, in any place in the world. The signals that are from the satellites are broadcasted to a device that is hand held on the ground. This device receives the signals from more than three satellites at any given time therefore using the principle of triangulation in order to determine where the user is positioned on the earth service. Traverse is a technique that employs use of line series whose directions and lengths are measured (Survey Advisory Board 2004). These lines connect points with the positions that need to be determined. Transverse may either be open or closed. Normally, the routes of the transverse lines may be adjusted for the obstacles like swampy land, timbered or rough terrain, heavy traffic or areas with large buildings. The open traverse does begin from a specific position or point and ends up in another point which is unknown. This type of transverse is mostly used for the survey of the highways. Closed traverse do begin and end at the same spot whose position is known. It is mostly used to measure the perimeter of lands. Leveling is the act of finding the differences in elevation through measuring the vertical distances directly by the use of a rod which is graduated. Other leveling instruments like the theodoites, transit and the dumpy level are also used(Dallas, Antonio, & Christi 2002 ). The indirect leveling is done by using the principles of the difference of the elevation which are proportional to atmospheric pressure differences. Differences in the elevation between two points are determined by the use of trigonometry which uses inclined distances, horizontal angles or the vertical angles. The radiation technique of surveying is usually used together with the plane table. Using a fixed position which is directly above the position which we are interested in on the ground, various bearings are taken on the various points on the boundary of the area of the survey (Dallas, Antonio, & Christi 2002 ). On the paper, these bearing lines are drawn. Then the distance to the points are measured then converted to the required scale on the survey sheet. The radiation surveying would be done in a similar manner directly on the ground through taking distances and bearings from a fixed position then recording them for the later work. Moreover, the plane table surveying could be used together with other techniques like triangulation and transverse. Global positioning satellite continuously broadcasts radio signals (Whensy, 2006, p. 98). This radio wave travels at a speed of light. To measure the distance from the satellite to the point of interest on the earth service, all we need to do is to measure how long it takes for the signal to reach the earth from the satellite and then multiply by the speed of light. Satellite broadcast have complicated digital decoder so that whenever a signal is sent from the earth service, a code is simultaneously generated on the satellite. The receiver is able to compare the two and measure the phase shift in order to determine the time difference. The topographic maps present accurate graphic representations that are detailed as it appears on the surface of the earth. Some of the features that may be included in the topographic maps include hydrography, relief, cultural and the vegetation (Holmberg, 2004 p. 28). Topographical maps therefore present the coordinate grid and the geographic graticule which helps to determine the absolute and the relative positions of the mapped features. However, compared land surveying techniques, the maps only presents the physical environments at a past time. The maps are two or three dimensional representation of the physical environment. The topographic maps are never entirely up to date since there are changes in cultural features, landscape among others that regularly occurs which would always result to the map becoming outdated. The site engineering is a branch of civil engineering that mainly deals with converting a land tract from being used in one way to another (Oregon B 2005). By the nature that they deal with small portions of land, the site engineering mostly use ground laid equipments to effect their surveys. This mostly includes the plane table. In conclusion, the technique used for land survey mostly depends on the type of the survey that is being conducted. Advanced systems use global positioning systems and are able to give updated data within a very short period of time. On the other hand, topographic mapping and site engineering takes time to develop which makes the output to be never entirely up to date since some changes would have occurred before the map is processed. References Oregon B 2005, ‘Basic Surveying theory and practice’, Geometronics, Vol. 1, no.1, pp. 8-73. Survey Advisory Board 2004, ‘Standards and Guidelines for Land Surveying ’, Global Positioning System Methods, Vol. 3, no. 3, pp. 291-305. Holmberg, J 2004, Land Measurement and Survey, Elsevier, Sydney. Trimpered, J 2009, ‘Overview of topographic surveying techniques and methods,’ Development in Survey Systems, Vol. 21, no. 6, pp. 645-665. Whensy, G, 2006, ‘Operations of modern surveyors,’ International Journal of Survey development, Vol. 2, no. 2, pp. 96-120. Dallas, Antonio, S & Christi, C 2002, Types of Survey & Surveying Techniques, Adelaide University, viewed 3 November 2011, . Read More