Definition of Surveying
Surveying is the art of measuring ground distance and area. It is used in many fields, including architecture, engineering, construction and land management.
An engineering survey is the gathering of data about the physical attributes of a particular area of land, water, or air. The purpose of an engineering survey is to provide information that can be used in the planning, design, and construction of engineering projects.
An engineering survey includes a wide range of activities, from the initial site investigation through to the final construction phase. The type of data collected during an engineering survey will vary depending on the project requirements. However, the data must be accurate and of the highest quality to ensure that the engineering project is completed successfully.
Types of Surveying
Surveying techniques vary by the type of survey and they are often specific to particular industries. There are two main types of surveying:
This surveying of areas of limited size, making no corrections for the earth’s curvature and its spherical shape, was a common practice in the ancients’ maps. The theory that the earth is spherical, with a curved surface, was not known until the 16th century. , and in the 18th century, the term “sphere” was not yet applied to maps, this is due to maps of that time being drawn according to theories of a flat earth.
Geodesy is the science of measuring and understanding the Earth. It is also the study of how shape, size, orientation, and gravitational forces affect the Earth’s surface. Geodesy can be done in two ways: by measuring distances and angles on the surface of Earth or by studying Earth from space.
Geodesy is an important field for map making because it helps to determine accurate positions for points on a map. Geodesists are scientists who study geodetic surveys in order to help with quality mapping projects and survey data collection.
Land surveying is the process of measuring, marking, and describing land parcels for the purpose of creating maps and legal descriptions. It is a critical component of land development, construction, and land management.
There are many different types of surveys, each of which serves a specific purpose. boundary surveys are used to establish the property lines of a parcel of land, topographic surveys are used to create maps of the land surface, and construction surveys are used to aid in the construction of buildings and other structures.
Surveying is a complex science that requires specialized training and equipment. However, the basic principles of surveying are not difficult to understand
Importance of Survey
These are the most critical survey techniques applications
The survey enables the setting out of the project site extent to allow for feasibility studies.
Setting out of project construction points coordinates by surveyors as set out on the construction drawings.
Surveyors set out boundaries that delineate different administrative units like continental, national, county, district and wards normally as shown on maps.
Reference points Triangulation
By conducting a traverse, project control points can be accurately set to the project specifications for construction. Surveyors are also able to stake all the positions of the high-level benchmarks for checking all the survey works.
Maps are made by surveyors. Oceanographers, geologists, archaeologists, and hydrographers all use maps in their daily lives. Many people have come across topographic and cadastral maps as they are the most used. Cadastral maps detail land use activities as delineated by land surveyors
Surveyors make maps that are used for navigation by pilots and captains all over the world.
The modern Surveying equipment?
There has been tremendous improvement in the technology for survey measurement equipment over the century. From the use of rudimentary tools to sophisticated hardware that is able to determine distances by optical capabilities or electronically through electronic distance measurement(EDM).
Surveying instruments-Horizontal and vertical measurements
A Total station
A total station is an electronic/optical instrument used in surveying and construction. It is a combination of an electronic theodolite and an electronic distance meter.
It is extremely versatile surveying equipment that can be used for a variety of tasks, such as measuring angles and distances, tracking moving objects, and even creating 3D models of objects.
If you’re involved in surveying or construction, then learning how to use a total station is a valuable skill. In this article, we’ll give you a basic overview of how total stations work and what they can be used for.
How does a total station work?
A total station is an electronic/optical instrument that is used for measuring angles and distances. It consists of a theodolite (a tool for measuring angles) and an EDM (electronic distance meter), which are combined with a computer and display.
The total station instrument is mounted on a tripod, and the operator uses the theodolite to target objects at a known or unknown location. The EDM then sends out a pulse of laser light or infrared radiation, which reflects off the object and back to the total station. Based on the time it takes for the light to travel back and forth, the distance to the object can be calculated very accurately.
Once the distance measurement has been made, the angular measurement can be taken. The operator first targets an object at a known location (such as another total station instrument), then moves the total station until this target is in the crosshairs of the telescope. By knowing the distance between these two objects, as well as their respective angles, it’s possible to easily and very accurately triangulate the position of the target. This method is known as resection.
A theodolite is a precision instrument used for surveying and measuring angles. It consists of a modern telescope mounted on a tripod, with various controls that allow the user to precisely measure angles. Theodolites are used in a variety of applications, from mapping the surface of the Earth to measuring the height of buildings and bridges.
If you need to measure something with precision, a theodolite is an instrument for the job. Whether you’re a professional surveyor or just need to take some measurements for a DIY project, a theodolite can help you get the job done right.
Also known as a transit, theodolites are simple to use. They focus on a target object, like a piece of construction or something that needs to be measured, in order to take precise measurements of altitude and azimuth (in other words: up-down elevation and side-to-side horizontal movement). If you need to measure something in 3D space with high accuracy (for example, if you’re surveying land), theodolites are the go-to instrument.
– Transit body style (the most common type) has a telescope that can rotate in a horizontal plane, allowing for the measurement of both horizontal and vertical angles
– Vertical circle graduation helps with measuring altitude
– Horizontal tangent screw lets you turn the telescope left or right without moving the entire instrument
– Level vials help make sure the instrument is level before taking measurements
Hand Held GPS
The GPS system
The GPS system is a constellation of 24 satellites that orbit the Earth. These satellites transmit signals that allow a GPS receiver to calculate its precise location. Global Position System receivers come in a variety of shapes and sizes, but all of them share the same basic functionality.
GPS receivers can be used for a variety of purposes, from navigation to tracking. They are an essential tool for anyone who needs to know their precise location, whether they are on land, at sea, or in the air. Global Position System receivers are used by hikers, sailors, pilots, and anyone who needs to know their exact location.
The Garmin GPSMAP 62s is a handheld GPS device that is perfect for use in the great outdoors. It features a high-sensitivity GPS receiver, a colour TFT display, and a built-in base map of the United States. The GPSMAP 62s also has a microSD card slot so you can add additional maps, and it is waterproof and durable for use in all conditions.
Personal use of handheld GPS
You may log the coordinates of a specific site, keep track of where you’ve been, and plan a route by using a handheld GPS unit or some GPS/satellite smartphone apps.
Having a GPS smartphone app or handheld gadget has the following benefits:
travelling without concern for being lost and being able to go anyplace
Since the gadgets, when they are turned on, keep track of your movements, you can always trace that trackback back to where you started. In order to follow them later, you may also store these tracks.
They can aid in finding items.
The coordinates of the places they want you to visit are frequently provided by the stewardship program, hiking websites, and federal agencies. Your gadget can direct you there if you enter these coordinates into it. This is excellent for locating a site or site features on a big site.
You can create your own points (coordinates)
which enables you to save a location’s coordinates for later retrieval. If you need to recall where you parked your car or tell the authorities where the damage to your site occurred, this is really beneficial.
You can give emergency services your precise location.
You should inform emergency personnel of your exact location in case you become injured or become stranded far from any highways. If you can tell emergency dispatchers where you are with pinpoint accuracy, they can send the coordinates to Search and Rescue so that they can use their GPS device to locate you.
Surveying Instruments for levelling
levelling is a survey technique used to determine the relative height of points on a given piece of land. It is often used in conjunction with other surveying techniques, such as trilateration, to determine more accurate data.
There are two main types of survey levelling: differential and trigonometric.
Differential survey levelling
This is the most common type and involves measuring the ground length between two points that are known to have a difference in height.
Trigonometric survey levelling
This involves taking measurements from three points and using trigonometry to calculate the height of the third point.
Survey levelling is a vital tool for any surveyor, as it allows them to produce accurate maps and drawings of the land. It is also used in the construction industry to ensure that buildings are built to the correct height.
The equipment used to measure the level is a dumpy level
A dumpy level is an optical surveying levelling tool that consists of a telescopic tube that is tightly fastened in two collars that are fixed to the stage by the vertical spindle with adjustable screws.
Dumpy Level’s telescope can only spin in a horizontal plane. With a dumpy level, the relative height of several places on surveying land is established.
William Gravatt, an English civil engineer, is credited with creating the dumpy level. Using the standard Y level, he created the dumpy level in 1832.
Another name for a dumpy level is a builder’s level or an automatic level.
A levelling staff is a tool used to measure the ground height difference between two places.
Staff readings are sighted directly by the instrument man from the levelling instrument. The levelling staff is also known as a staff rod, levelling rod, and self-reading staff.
Surveying instruments to determine bearing and directions
Angles are created when the direction is determined in relation to each other. Bearing refers to a direction that has been determined in relation to a meridian.
It consists of a graduated metal circular ring with a magnetic needle connected to it. If the needle is on the pivot, it automatically aligns with the magnetic meridian. The compass box is equipped with an eye slit and object vane that aid in determining the line of sight.
The device that calculates the magnetic meridian is a magnetic compass. It is also convenient because it is portable. It can be mounted on a tripod or used in the palm.
A surveyor’s compass is an instrument for measuring direction in relation to the magnetic meridian. The Circumferentor is the popular name for the Surveyor compass.
Essentially, it is made up of a sighting tool, a magnetic needle that is rotated, and a graduated horizontal circle.
Plane Table Surveying instruments
Plane table surveying is a method of mapping that uses a plane table, alidade, and paper or tracing cloth to transfer measurements from the field to a map. It is a slower method of surveying than GPS or total station surveying, but it has several advantages. Plane table surveying is more accurate than GPS surveying, and it is also more portable and easier to set up.