16 Questions
EDM instruments use infrared light or laser light to determine lengths.
True
Total stations are used to measure only horizontal distances.
False
EDM instruments can measure distances up to 50 km.
False
The best quality total stations can measure angles to 1 arc-second.
False
Total stations use a prism reflector to reflect the modulated microwave or infrared carrier signal.
True
EDM instruments are used to measure the vertical distance between two points.
False
Total stations use trigonometry and triangulation to calculate coordinates.
True
1 degree is equal to 1800 arc-seconds.
False
What is the primary principle of EDM instruments?
Determining distances using phase changes of electromagnetic energy
What type of range does a short-range EDM instrument cover?
0.5-3 km
What is the purpose of the prism reflector in total stations?
To reflect the modulated microwave or infrared carrier signals
How do total stations measure angles?
Through electro-optical scanning of digital bar codes
What is the unit of measurement for angles in high-quality total stations?
Arc-second
How do total stations calculate coordinates?
Using trigonometry and triangulation
What is the relationship between degrees and arc-seconds?
1 degree is equal to 3600 arc-seconds
What is the purpose of an EDM instrument in surveying?
To measure horizontal distances between two points
Study Notes
Electronic Distance Measurement (EDM)
- EDM determines lengths using phase changes that occur as electromagnetic energy of known wavelength travels from one end of a line to the other end and returns.
- EDM instruments use laser light or microwaves to measure distances.
- Uses of EDM instruments include:
- Measuring the horizontal distance between two points
- Measuring distances with the help of a reflector held by a second surveyor
- EDM instruments come in three types:
- Long-range (10-20 km)
- Medium-range (3-10 km)
- Short-range (0.5-3 km)
Total Station
- A total station is an electronic/optical instrument used in modern surveying and building construction.
- It integrates an electronic theodolite with an electronic distance meter.
- Uses of a total station include:
- Coordinate measurement: Measuring angles and distances to calculate coordinates (Y, Z or easting, northing, and elevation) of surveyed points.
- Angle measurement: Measuring angles using electro-optical scanning of digital bar codes with an accuracy of 0.5 arc-seconds.
- Distance measurement: Measuring distances using a modulated microwave or infrared carrier signal reflected by a prism reflector or the object under survey.
- Data processing: Recording distance, horizontal angle, and vertical angle measurements internally or externally, and downloading data to a computer to compute results and generate a map of the surveyed area.
Electronic Distance Measurement (EDM)
- EDM determines lengths using phase changes that occur as electromagnetic energy of known wavelength travels from one end of a line to the other end and returns.
- EDM instruments use laser light or microwaves to measure distances.
- Uses of EDM instruments include:
- Measuring the horizontal distance between two points
- Measuring distances with the help of a reflector held by a second surveyor
- EDM instruments come in three types:
- Long-range (10-20 km)
- Medium-range (3-10 km)
- Short-range (0.5-3 km)
Total Station
- A total station is an electronic/optical instrument used in modern surveying and building construction.
- It integrates an electronic theodolite with an electronic distance meter.
- Uses of a total station include:
- Coordinate measurement: Measuring angles and distances to calculate coordinates (Y, Z or easting, northing, and elevation) of surveyed points.
- Angle measurement: Measuring angles using electro-optical scanning of digital bar codes with an accuracy of 0.5 arc-seconds.
- Distance measurement: Measuring distances using a modulated microwave or infrared carrier signal reflected by a prism reflector or the object under survey.
- Data processing: Recording distance, horizontal angle, and vertical angle measurements internally or externally, and downloading data to a computer to compute results and generate a map of the surveyed area.
Learn about EDM, a technique used to determine lengths by measuring the phase changes of electromagnetic energy. Discover the types of EDM instruments and their uses.
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