Surveying

Map  Scale Scale is required on maps to measures and to know the distance between any two points or objects. A scale is the ratio of length between two point on a map to its corresponding distance on the ground. To say that if a map is on the scale 1:25.000 means that a length of 1cm on the map represents 25000 centimeters or 250 m on ground. In other words, 250m distance on ground shown by a length of 1cm on the map. Expression of Scale Scales can be expressed in the following manner: 1) The statement scale 2) The RF / Numerical scale  3) The plain / linear / Graphical scale  1) The statement scale   In this case, the numbers of units on map that represent the corresponding number of units on ground are staled for. e.g.    1cm=200m; 4 cm  = 1 km , one inch to a mile; etc Now-a-day this system is not in more used 2)   The RF / Numerical scale    In this case, the proportion existing between the length on the map and the actual length on the ground is indicated

History of surveying Surveying Surveying is an art and science of determining the relative positions of points on,  above or beneath the surface of the earth by the means of direct or indirect  measurement of distance, direction and elevation and to depict them in a useable  form. Is is also includes the art of establishing points by predetermined angular   and linear measurement. History of surveying in world. • Surveying is perhaps as old as human civilization. The Babylonians practiced some type of surveying as early as 2500 BC. Surveying in some form was used in India and egypt to divide the land for taxation purpose in 1400 BC • • • • The earliest preserved writing on surveying about 150-100 years BC in greek. Heron invented survey instrument Dioptra. He describes the method of area calculation of triangle. Roman's invented hodometer to measure the distance between the cities. In 1571 Thomas Digges an english  mathematician known as father of modern surveying invented a instru

        LINEAR MEASUREMENT Content  Introduction & Principle  Slope, Horizontal, vertical distance  Direct & Indirect linear measurement method  Optical Distance Measurement (ODM)  Electronic Distance Measurement (EDM)  Linear survey (Chain Survey)   Field procedure & plotting  Obstacles in linear survey and their solution  Error in linear measurement 1.   Introduction and principle Linear Measurement   Chain survey is branch of surveying in which the distances are measured with a chain and tape and the operation is called chaining. chain Surveying is that type of surveying in which only linear measurements are made in the field. This type of surveying is suitable for survey of small extent on open ground having few simple details.  The principles of chain surveying are triangulation. As we know triangle is the simplest 2D figure whose area can be calculated easily and it is only the figure which can be plotted without any angle. According to this principle the area of surv