Types of Linear Measurement Surveying

In surveying, which is the science of determining the relative positions of points on the Earth's surface, there are several types of linear measurements used depending on the specific requirements of the survey.

Some of the common types of linear measurement in surveying include:

1. Chain Surveying: Chain surveying is one of the oldest methods of linear measurement in surveying.

   It involves the use of a chain (commonly known as a surveyor's chain) to measure distances between survey points.

   The chain is usually made up of links, and each link represents a specific unit of length (e.g., feet or meters).

2. Tape Measure Surveying: Instead of using a chain, tape measures are used to measure distances in tape measure surveying.

   The tape is typically made of steel or fiberglass and comes in various lengths and units of measurement.

3. EDM (Electronic Distance Measurement): Electronic Distance Measurement uses electronic instruments to measure distances between points.

   These instruments emit a laser or infrared beam, and the distance is calculated based on the time it takes for the beam to reflect back to the instrument.

   EDM is faster and more accurate than chain or tape measurement.

4. Total Station: A total station is an advanced surveying instrument that combines electronic distance measurement (EDM) with electronic theodolites.

   It can measure distances, horizontal angles, and vertical angles simultaneously, allowing for precise and efficient surveying.

5. GPS (Global Positioning System): GPS is a satellite-based navigation system that can be used for surveying to determine accurate positions on the Earth's surface.

   GPS receivers can provide highly precise and global positioning information.

6. Measuring Wheels: Measuring wheels, also known as surveyors' wheels, are used to measure linear distances by rolling the wheel along the ground.

   The rotation of the wheel is converted into distance measurements.

7. Traversing: Traversing involves measuring a series of connected straight-line distances and angles to establish the positions of various points relative to a starting point.

   It is often used for boundary surveys and establishing control points.

8. Chaining and Taping: In this method, a chain or tape measure is used along with compass and theodolite readings to measure distances and angles for small-scale surveys.

several types of linear measurements are used to accurately represent distances and dimensions of land, buildings, and other features.

Here are some common types of linear measurement techniques used in surveying:

1. Tape Measure: The simplest and most straightforward method, where a tape measure is used to measure distances on the ground directly. This method is suitable for short distances and rough surveys.

2. Chain Surveying: In this traditional method, chains or chains with links are used to measure distances on the ground. The length of the chain can vary, but it is often standardized to be 66 feet (20.12 meters) or 100 feet (30.48 meters). Chain surveying is more accurate than tape measure surveys and is commonly used for small to medium-sized areas.

3. EDM (Electronic Distance Measurement): Electronic distance measurement instruments, such as total stations and theodolites equipped with electronic distance measurement capabilities, are used to measure distances with high precision. These instruments use electromagnetic waves to determine distances between points.

4. GPS (Global Positioning System): GPS technology utilizes satellites to determine precise positions and distances on the Earth's surface. It provides accurate global positioning information, making it an essential tool for large-scale surveys and geodetic measurements.

5. Trilateration: Trilateration is a technique that uses distances between known points (control points) and an unknown point to determine the location of the unknown point. It is commonly used in combination with GPS or EDM measurements.

6. Triangulation: Triangulation is a method of determining distances and angles by creating triangles between known points and an unknown point. It is commonly used for large-scale surveys and mapping.

7. GPS/GNSS RTK (Real-Time Kinematic): This technique uses GPS or GNSS (Global Navigation Satellite System) signals to obtain real-time, centimeter-level positioning accuracy. It is commonly used in construction, land surveying, and geodetic applications that require high precision.

8. Photogrammetry: Photogrammetry involves using aerial photographs or images taken from drones to measure distances and create three-dimensional models of the surveyed area. It can be used for mapping large areas and capturing detailed topographical information.

These different types of linear measurement surveying techniques offer varying levels of accuracy and are selected based on the specific requirements of the surveying project and the desired level of precision.

The choice of method depends on factors such as the size of the area to be surveyed, the level of detail needed, budget constraints, and available technology.

Modern surveying techniques often combine various types of linear measurements to achieve the desired results efficiently and accurately.