Land surveying, which involves measuring the distance, directions, and elevations to determine the shape of the earth's surface, requires special land surveying equipment to enable surveyors to make accurate measurements.
There are various types of land surveying equipment, some that range from the very basic, which requires no additional training or licensing, to more high-tech versions, which may require additional training. Some of the most common types of land surveying equipment include:
A theodolite, which includes an infrared, a laser, and an electronic decoder, looks similar to a telescope and has a readout screen that is used to show vertical and horizontal angles. There are also nondigital theodolites; however, they are not used quite as often.
The theodolite, especially the digital version, is often preferred for its technology, which enables surveyors to make more accurate measurements. It operates by allowing the surveyor to peer through the telescope and then lock in the image to be measured. The instrument then rotates around in both vertical and horizontal directions to measure the object's vertical and horizontal angles. It can also be used to determine elevations.
The satellite and GPS also called place surveying equipment, are important because they allow the surveyor to identify the boundaries of an area. They can also be used to document any variations on the ground. The satellite and GPS system generally operates by utilizing a GPS antenna to send broadcast signals to the satellite.
The satellite, which spins around the earth, then communicates the signal to the GPS receiver carried by the surveyor, at which time it enables the surveyor to take various precise measurements of different land coordinates.
Using the satellite and GPS system gives the surveyor access to updated information via a laptop, which is set up with surveying software. The GPS receiver, in addition to other hand-held electronic devices, then serve as data collectors.
The compass is a basic instrument that is used to measure the course of a line, using a suspended needle that points north as its point of reference.
There are two main types of compasses: a vernier compass and a plain compass. A vernier compass consists of an adjustable scale that allows for the correction of the magnetic declination so the compass can read true north, while a plain compass needs no adjustment because it always points true north. The surveyor uses the compass by rotating it in the direction of the line being examined so that the line of the direction can be observed.
A level is used to calculate elevations.
There are various types of levels; however, the three main types of levels are the dumpy level, the automatic level, and the Wye level.
A dumpy level contains a telescope with crosshairs positioned on a pair of arms and is typically used in building to find elevations. The telescope of the dumpy level revolves to allow for measurements in all directions, and it can also magnify from twenty to thirty times. It also has spirit levels built into its base to ensure the device is level so that accurate measurements can be taken.
An automatic level is similar to a dumpy level, except it includes a compensator that instantly adjusts for slight errors in the equipment set up, and the Wye level has a telescope with crosshairs that are detachable from the arms.
Which level the surveyor uses typically depends on the degree of accuracy that is needed. A level generally stands on a tripod, which allows it to be steady while taking measurements.
A stable tripod is essential for gathering precise measurements.
The legs of the tripod are made of fiberglass, wood, or aluminum and are adjustable for use with various pieces of surveying equipment. Fiberglass tripods are heavier to carry through the field; however, wood or aluminum tripods are lighter and can influence readings in certain weather conditions.
The head of the tripod is either dome or flat. Dome heads allow for more adjustment, while flatheads are easier to fit but have less play. They also come in different thread sizes to adapt to newer equipment.
Tapes and Chains
Tapes and chains are steel tapes that are used to measure linear distances and are considered the easiest way of taking measurement because they are only utilized on the field while the remainder of the survey is being completed in the office.
Tapes and chains are typically handled with clamp or tension handles in order to apply pressure and prevent damage to the tape as well as the surveyor's hands.
Standard tapes and chains come in various lengths from 100 feet to 500 feet, and they can be wrapped on a wheel or gathered in loops.
Land Surveying Equipment Training
Surveying equipment requires an understanding of the intricacies of measuring angles, computing land mass areas, and calculating averages as well as an understanding of global positioning technologies, electromagnetic instruments, and other specialized equipment to obtain spatial data and perform data reduction.
Professional land surveyors are required by employers to have at least an associate's degree in survey technology, which includes training in modern surveying equipment, as well as state licensing through their local board. However, because surveying equipment is ever-changing, professional surveyors typically undergo ongoing education.
But, if you are a property owner who is just curious where your legal property line is, and you have a working knowledge of measuring, calculating, and computing land instruments, you can perform an approximate land survey yourself. But be warned, because it is not official, it may not be admissible in legal matters.
About the Author
Dennis McCaffrey is a Land Surveyor for Empire State Layout, leading Expert Land Surveyors for NYC, Manhattan, The Boroughs, Nassau County, Suffolk County, Long Island, and the Surrounding Area. Learn more by visiting their website.