levelling by height collimation method

Height collimation techniques play a pivotal role in surveying and geomatics, enabling the establishment of a horizontal line of sight at a specific elevation above a reference point or datum. These methods are instrumental in achieving precise measurements for applications ranging from construction to land surveying and topographic mapping.

Level Instrumentation

Utilizing specialized leveling instruments like dumpy levels or theodolites, this method involves setting up and leveling the instrument on a known reference point. The line of sight is then adjusted to the desired height, ensuring accurate measurements.

Trigonometric Levelling

Leveraging trigonometric principles, this technique calculates the height differential between two points based on observed angles and distances. Particularly valuable in scenarios where direct leveling is impractical due to obstacles or extensive distances.

Barometric Levelling

This method relies on atmospheric pressure readings to estimate height variances between two points. However, it is sensitive to fluctuations in weather conditions.

Global Positioning System (GPS)

Modern GPS technology offers a means to determine heights above a reference ellipsoid. Differential GPS techniques further enhance accuracy in vertical positioning.

Photogrammetric Analysis

Through overlapping aerial photographs and specialized software, this method derives height information with precision, aiding in the creation of detailed topographic maps.

Laser Scanning and LiDAR

Cutting-edge technologies such as laser scanning and LiDAR generate intricate 3D models of terrain, providing highly accurate height data.

Conclusion

Each of these height collimation methods presents distinct advantages and limitations, with the choice depending on factors including required accuracy, terrain characteristics, and available equipment and resources. Adherence to established procedures and best practices is crucial to ensure the reliability and accuracy of height measurements.

Application of height collimation method

height collimation method is widely utilized across various industries where precise elevation measurements are imperative. This technique plays a pivotal role in ensuring accuracy in a multitude of applications.

Construction Industry

  • Setting Benchmarks and Establishing Elevations
  • Ensuring Correct Structural Heights

Land Surveying

  • Accurate Elevation Determination for Land Features
  • Essential for Property Development and Boundary Disputes

Topographic Mapping

  • Depicting Vertical Dimensions in Cartography
  • Vital for Accurate Representation of Terrain

Civil Engineering

  • Integral in Infrastructure Projects
  • Ensuring Correct Elevation in Road and Bridge Construction

Environmental Monitoring

  • Tracking Land Elevation Changes
  • Important for Studying Natural and Human-Induced Environmental Phenomena

Geological Surveys

  • Measuring and Recording Elevation Changes in Geological Formations
  • Enhancing Understanding of Geological Processes

Urban Planning

  • Accurate Assessment of Building and Urban Feature Elevations
  • Crucial for Zoning and Land-Use Planning

Flood Risk Assessment

  • Determining Elevation of Flood-Prone Areas
  • Essential for Assessing and Planning Flood Control Measures

Mining and Quarrying

  • Determining Elevations in Extraction Operations
  • Vital for Efficient Mining and Quarrying Practices

Agricultural Engineering

  • Ensuring Proper Drainage, Irrigation, and Land Grading
  • Critical for Effective Agricultural Practices

Astronomy

  • Accurate Measurement of Celestial Altitudes
  • Essential for Celestial Navigation and Observations

Conclusion

In a wide array of applications, the accurate determination of height in relation to a reference point or datum is paramount for the success and dependability of projects or studies. The height collimation method stands as a linchpin in achieving this level of precision.

Investigation Survey” by Oran Viriyincy is licensed under CC BY-SA 2.0.

The readings were taken with a level staff of 4m, BM =150.

3.385, 1.73, 0.615, 3.45, 2.835, 2.560, 1.835, 0.985, 0.435, 1.450, 2.255 and 3.420 m.

Steps to find RL & HI

  • write all the given data BS, IS and FS reading.

BS = first reading taken, (initial point/after changing instrument position)

IS = all the readings taken between BS and FS

FS = last reading taken before changing the instrument position.

  • calculate the RL value

first RL = BM

RL = HI – IS/FS

  • calculate HI (height of instrument)

HI = RL + BS

add the corresponding RL value with diffrence value to get new RL.

  • Check for errors by using arthmetic check formula –

Sum of BS – Sum of FS = Last RL – First RL

Sl. No.BSISFSHI = RL + BSRL = HI – IS/FSRemarks
13.385153.385150BM = 150
21.73151.655
30.615152.77
42.8353.45152.77149.935
52.56150.21
61.835150.935
70.4350.985152.22151.785
81.45150.77
92.255149.965
103.42148.8
Sum∑BS = 6.655∑FS = 7.855

Arithmetic Check

Sum of BS – Sum of FS = Last RL – First RL

Sum of BS – Sum of FSLast RL – First RL
6.655 – 7.855148.8 – 150
-1.2 -1.2

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