![]() ![]() A bronze plate provided on the top of a concrete pedastal with elevation engraved on it serves as benchmark. GTS benchmarks are established all over the country with highest precision survey, the datum being mean sea level. In India, the department of Survey of India is entrusted with such works. These benchmarks are established by national agency. ![]() (a) GTS Benchmark: The long form of GTS benchmark is Great Trigonometrical Survey benchmark. (c) Arbitrary benchmarks and (d) Temporary benchmarks. (a) GTS benchmarks (b) Permanent benchmarks The following are the different types of benchmarks used in surveying: It is used as a starting point for levelling or as a point upon which to close for a check. Benchmarks: A benchmark is a relatively permanent reference point, the elevation of which is known (assumed or known w.r.t. Reduced Levels (RL): The level of a point taken as height above the datum surface is known as RL of that point.ħ. In all important surveys this is used as datum.Ħ. In India MSL used is that established at Karachi, presently, in Pakistan. At any particular place MSL is established by finding the mean sea level (free of tides) after averaging tide heights over a long period of at least 19 years. Mean Sea Level (MSL): MSL is the average height of the sea for all stages of the tides. Datum: The level of a point or the surface with respect to which levels of other points or planes are calculated, is called a datum or datum surface.ĥ. Vertical and horizontal lines at a point are at right angles to each other. Vertical Line: A vertical line at a point is the line connecting the point to the centre of the earth. Hence a horizontal line is at right angles to the plumb line at that point. Horizontal Surface: A surface tangential to level surface at a given point is called horizontal surface at that point. Figure 15.1 shows a typical level surface.Ģ. Hence all points lying on a level surface are equidistant from the centre of the earth. Level Surface: A surface parallel to the mean spheroid of the earth is called a level surface and the line drawn on the level surface is known as a level line. The upcoming summit will provide an opportunity for leaders to find a balance between meeting the benchmark and addressing economic constraints.Before studying the art of levelling, it is necessary to clearly understand the following terms used in levelling:ġ. However, the debate over meeting the two percent target is complicated by economic factors and varying priorities among NATO members. In conclusion, Canada’s push to expand the definition of NATO’s defence spending benchmark reflects the evolving nature of modern warfare and the increasing importance of space, cyber, and AI capabilities. ![]() ![]() NATO leaders will need to address the economic realities and budget constraints faced by member countries while ensuring that the alliance remains strong and capable of addressing emerging security challenges. The upcoming NATO summit in Vilnius, Lithuania, will be a crucial moment for discussions on defence spending and the expanded definition of the benchmark. Eastern European countries, particularly those closest to Russia, are more eager to meet the goal, while Western European countries show less enthusiasm. This raises questions about whether countries like Spain will be able to aggressively reduce their deficits and increase defence spending. Germany, for example, has expressed the need to focus on deficit reduction. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |