Introduction to Civil Engineering
Surveying or land surveying is the technique, living, art, and science of determining the earthly or three-dimensional positions of points and the distances and angles between them. A land surveying professional is called a land surveyor. These points are typically on the surface of the Earth, and they are often used to found maps and boundaries for ownership, locations, such as building corners or the surface location of subsurface features, or other purposes compulsory by government or civil law, such as property sales. Surveyors work with elements of geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages, and the law. Surveying has been a part of the development of the human environment since the beginning of logged history. The planning and execution of the greatest forms of construction require it. It is also used in transport, communications, mapping, and the description of legal boundaries for land ownership. It is an important tool for research in numerous other scientific disciplines. A survey that founds or re-establishes boundaries of a parcel using a legal description. It involves the restoration of monuments or markers at the corners or sideways the lines of the parcel. These take the form of iron rods, pipes, or concrete shrines in the ground, or nails set in concrete or asphalt. A survey steered with the purpose of mapping the shoreline and bed of a body of water. Cast-off for navigation, engineering, or resource management purposes. Survey to change base flood line, removing belongings from an SFHA special flood hazard area. A building survey to plans of the building. such a survey may be conducted previously renovation works, for commercial purposes, or at end of the construction process. Mining surveying includes leading the digging of mine shafts and galleries and the calculation of the volume of rock. It uses specialized techniques due to the chains to survey geometry such as erect shafts and narrow passages. A detailed inspection to report upon the physical condition and structural stability of a building or structure. It highlights any work desirable to maintain it in good repair. A survey that procedures the elevation of points on an exact piece of land, and presents them as contour lines on a plot. A total station (TS) or total station theodolite (TST) is an electronic/optical instrument cast-off for surveying and building construction. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the instrument to a precise point, and an on-board computer to collect data and achieve triangulation calculations. Robotic or motorized total stations agree with the operator to control the instrument from a distance via remote control. This eliminates the need for an associate staff member as the operator holds the retroreflector and controls the total station from the experimental point. These motorized total stations used in automated setups know as Automated Motorized Total Station (AMTS). Total stations are largely used by land surveyors and civil engineers, either to record landscapes as in topographic surveying or to set out features (such as roads, houses, or boundaries). They are also used by archaeologists to record excavations and by police, crime part investigators, private accident re-constructionists, and insurance companies to take measurements of scenes. Total stations are the chief survey instrument used in mining surveying. A total station is used to record the total location of the tunnel walls, ceilings (backs), and floors as the drifts of an underground mine are determined. The recorded data are then copied into a CAD program, and compared to the designed layout of the tunnel. The survey party connects control stations at regular intervals. For wall stations, two plugs are installed in opposite walls, forming a line perpendicular to the drift. For back stations, two plugs are installed in the back, creating a line parallel to the drift. A set of plugs can be used to trace the total station set up in a drift or tunnel by giving out measurements to the plugs by intersection and resection. Total stations have developed the highest standard for most forms of construction layout. They are most often used in the X and Y axis to lay the locations of penetrations out of the underground conveniences into the foundation, between floors of a structure, as well as roofing penetrations. Because more commercial and industrial construction jobs have to convert centers around building information modeling (BIM), the manages for every pipe, conduit, duct, and hanger support are accessible with digital meticulousness. [clarification needed]. The application of collaborating a virtual model to a perceptible construction eradicates labor costs related to moving poorly measuring systems, as well as time putting out systems in the of a full-blown construction job in progress. Meteorologists use total stations to track weather balloons for upper-level winds. With the average ascent rate of the meteorological conditions balloon known or assumed, the change in azimuth and elevation readings provided by the total station as its pathways the balloon over time are used to calculate the wind speed and direction at different altitudes. Tachometry Full-scale mapping can be accepted out using survey instruments to position landscapes and connect them into a network of measured triangles using the procedures of tachometry. Taking the level instrument itself, place it on top of the tripod and by means of the screw rod under the apex screw it into the tripod, but not fully tight up until after finalizing the levelling process. To make the level sight horizontally the bubble in the oil-filled capsule must be made to rest in the graduated circle. This is achieved by moving the level around slowly on top of the tripod until the bubble carried to rest in the circle. Once the level look is done the telescope and brings some distant objects into focus. Now turn the eyepiece itself till the crosshairs are sharply in focus at the same time as the distant object. The crossing point of the two long lines at the centre is the horizontal level well-definite by the instrument. Practice focusing on the levelling staff and scholarship to read the graduations which are clear in 5 cm high 'E' shapes: first read the large number below the crosshairs, then estimate the two-figure number in mm up the 'E' shape and in conclusion add together to get a reading (e.g., 1.933 m). Remember that the staff must be apprehended vertically to reduce errors. Plane tabling First you need to establish a baseline on the ground of an appropriate length (decide what is appropriate) using a measuring tape. This should be at right angles to the feature to be mapped, e.g., a salt marsh brook. Place a peg in the ground at each end of the baseline: these are the ‘stations. Now the traffic plane table to one of the stations. Screw the tripod into the table and adjust the legs so that the table stands level and unchanging. Second, fix the paper squarely to the table by means of the masking tape; then get out the alidade and unfold the sights. Merely measure a compass bearing as accurately as you can to each of the landmarks and correct them for a magnetic variation to true north, rather using a sighting compass. Then draw a line from each landmark on the map at the angle of the bearing. They ought to meet at a point, which is the current position. If there are errors in the bearing, then the lines may form a small triangle, which is a zone of indecision, known as a ‘triangle of error’. When checking or altering bearings to reduce these errors, bear in the awareness that the amount of each error – the amount of ‘swing’ from the true bearing - will be proportional to the length of that line. Tape and compass traverse Basic surveys of small areas can be passed out using a surveyor’s tape and a compass to measure the length and orientation of features that can visit and delineate e.g., archaeological remains. Distances will only be true if the tape is straight and unknotted: this can be hard to guarantee in windy conditions, in flowing water, or where there is thick vegetation. Compass ‘bearings’ are measured virtual to magnetic north and need to be corrected to true north by a small ‘magnetic variation’ angle to account for the fact that the magnetic north pole is in a little different place to the geographic north pole and is moving slowly in a process known as ‘magnetic declination’. Contouring Using a barometer (or GPS receiver), and where it is physically practical to do so, can try to walk ‘around’ a hill or ‘across’ a slope while remaining at the same height. The advanced developments in digital data processing, the nature of the professional land surveyor has evolved and the term "surveying" no longer accurately covers the whole range of tasks that the professional transactions with. As our societies become more complex, information with a spatial position connected with it converts critical to decision-making, both from a personal and a business perspective, and a community and a large-scale governmental viewpoint. The geomatics engineer can be elaborate in an extremely wide variety of information gathering activities and applications. Geomatics engineers design, develop, and operate systems for collecting spatial information near the land, the oceans, natural resources, and manmade features. The more outdated land surveying strand of geomatics engineering is concerned with the determination and recording of boundaries and areas of real property parcels, and the preparation and interpretation of legal land descriptions. The responsibilities more closely linked to civil engineering embrace the design and design of public infrastructure and urban subdivisions, and mapping and control surveys for construction projects. Geomatics engineers help society by collecting, monitoring, archiving, and maintaining spatial data infrastructures. Geomatics engineers apply a wide range of scientifically advanced tools such as digital theodolite/distance meter total stations, Global Positioning System (GPS) equipment, digital aerial imagery (both satellite and air-borne), and computer-grounded geographic information systems (GIS). These tools permit the geomatics engineer to gather, process, analyze, visualize, and accomplish spatially connected information to solve a wide range of technical and societal problems. Stands for "Global Positioning System." GPS is a satellite navigation system used to determine the ground place of an object. GPS technology was first cast-off by the United States military in the 1960s and expanded into civilian use over the next few decades. Today, GPS receivers are encompassed in many commercial products, such as automobiles, smart phones, exercise watches, and GIS devices. The GPS includes 24 satellites positioned in space about 12,000 miles (19,300 kilometres) upstairs the earth's surface. They orbit the earth once every 12 hours at a very fast pace of roughly 7,000 miles per hour (11,200 kilometres per hour). The satellites are evenly spread out so that four satellites are available via direct line-of-sight from anywhere on the globe. Each GPS satellite broadcasts a message that comprises the satellite's current position, orbit, and exact time. A GPS receiver combines the transmissions from multiple satellites to calculate its exact position using a process called triangulation. Three satellites are required to regulate a receiver's location, nevertheless, a connection to four satellites is ideal since it offers greater accuracy. For a GPS device to work properly, it must first establish a connection to the obligatory number of satellites. This process can take anywhere from a few seconds to a few minutes, depending on the strength of the telephone. For example, a car's GPS unit will naturally establish a GPS connection faster than the earpiece in a watch or Smartphone. By memorizing its previous location, a GPS device can quickly regulate what satellites available the next time it scans for a GPS signal. Since GPS receivers require a moderately unhindered path to space, GPS knowledge is not ideal for indoor use. Therefore, smart phones, tablets, and other mobile devices often use other means to limit location, cell towers, and public Wi-Fi signals. This technology, denoted as the local positioning system (LPS), is regularly used to supplement GPS when a consistent satellite connection is unavailable. GPS boosts the productivity of the economy, to contain farming, construction, mining, surveying, package delivery, and logistical supply chain management. Major infrastructure networks, banking systems, financial markets, and power grids depend upon the heavily on GPS for exact time synchronization. GPS saves lives by preventing transportation accidents, helping search and speeding the delivery of emergency services, and disaster relief. GPS is energetic to the Next Generation Air Transportation System (Next Gen) that will augment flight safety while increasing airspace capacity. GPS also loans scientific aims such as climate forecasting, earthquake monitoring, and environmental protection. A digital elevation model (DEM) is a 3D CG representation of a terrain's surface – normally of a planet (e.g., Earth), moon, or asteroid – fashioned from a terrain's elevation data. A "global DEM" states to a discrete global grid. DEMs are used repeatedly in geographic information systems and are the shared basis for digitally-produced relief maps. While a digital surface model (DSM) useful for landscape modeling, city exhibiting, and picturing applications, a digital terrain model (DTM) is often for flood or drainage modeling, land-use studies, geological applications, and other applications, and in planetary science. Extracting terrain strictures for geomorphology Modeling soils wetness with Cartographic Depth to Water Indexes (DTW-index). Creation of relief maps. Rendering of 3D visualizations. 3D flight planning and TERCOM Creation of physical models (including raised-relief maps). Rectification of aerial photography or satellite imagery. Reduction (terrain correction) of gravity measurements (gravimetry, physical geodesy) Terrain examination in geomorphology and physical geography Geographic information systems (GIS). Engineering and infrastructure design. LIDAR is a method for measuring distances (ranging) by enlightening the target with laser light and measuring the reflection with a sensor. Changes in laser return times and wavelengths can then be used to make digital 3-D representations of the target. It has terrestrial, airborne, and mobile applications. The term lidar was first a portmanteau of light and radar. It is also used as an abbreviation of "light detection and ranging" and "laser imaging, detection, and ranging". Lidar sometimes is called 3-D laser scanning, a special combination of a 3-D scanning and laser scanning. Lidar is frequently used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, atmospheric physics, laser guidance, airborne laser swath mapping (ALSM), and laser altimetry. The knowledge is also used in control and navigation for some autonomous cars. A LIDAR instrument chiefly consists of a laser, a scanner, and a specialized GPS receiver. NOAA scientists are using LIDAR to crop more accurate shoreline maps, make digital elevation models for use in geographic information systems, to assist in emergency rejoinder operations, and in many other applications. As it turns out, the accuracy of the laser ranging is truly one of the most accurate components in the whole system. Although airborne LiDAR systems may not be this accurate, as it chances out the error contribution from the laser ranging is by far one of the least significant sources of overall error. A lidar instrument principally contains a laser, a scanner, and a specialized GPS receiver. Airplanes and helicopters are the most normally used platforms for acquiring lidar data over comprehensive areas. Two types of lidar are topographic and bathymetric. Topographic lidar characteristically uses a near-infrared laser to map the land, although bathymetric lidar uses water-penetrating green light to also measure seafloor and riverbed elevations.
Unit - 13
Surveying & Geomatics
Q1) What is Surveying?
A1)
Q2) Explain the Types of Surveying?
A2)
1) Cadastral or boundary surveying:
2) Hydrographic survey:
3) LOMA survey:
4) Measured survey:
5) Mining surveying:
6) Structural survey:
7) Topographic survey:
Q3) Explain Total Stations and also give its applications.
A3)
Application:
1) Mining:
2) Mechanical and electrical construction:
3) Meteorology:
Q4) What are Traditional surveying techniques? Explain
A4)
Q5) What is Geomatics Engineer? Explain
A5)
Q6) Explain GPS. Write its applications.
A6)
Application:
Q7) Explain Development of Digital Terrain Models.
A7)
Method:
1) Lidar
2) Radar
3) Stereo photogrammetry from aerial surveys
4) Structure from motion / Multi-view stereo applied to aerial photography.
5) Block adjustment from optical satellite imagery
6) Interferometry from radar data
7) Real-Time Kinematic GPS
8) Topographic maps
9) Theodolite or total station
10) Doppler radar
Uses:
Q8) What is LIDAR?
A8)
Agriculture:
1) Archaeology
2) Autonomous vehicles
3) Biology and conservation
4) Geology and soil science
5) Atmosphere
6) Law enforcement
7) Military
8) Mining
0 matching results found