Table of Contents
Introduction
Systematic and random errors are very common in surveying. In surveying, it’s crucial to recognize the potential for both systematic and random errors in measurements.
An error represents the variance between our measured value and the actual truth. Every measurement inherently contains some degree of error since achieving absolute precision is unattainable.
Nevertheless, we can endeavor to reduce errors by employing proficient techniques and precise equipment. Determining the genuine value of a measurement entails taking numerous measurements and computing the average.
Systematic Errors In Surveying
Systematic errors in surveying are those errors identifiable by their consistent size and direction, thereby facilitating corrective actions to enhance the accuracy of measurements. An illustration of such an error involves the phenomenon of thermal expansion affecting the measurements taken with a steel tape.
When subjected to higher temperatures, the steel tape expands, resulting in an elongation beyond its nominal length. For instance, a 100-ft steel tape might extend to 100.015 ft under such conditions, presenting a systematic error of 0.015 ft. However, through an understanding of this phenomenon, surveyors can mitigate its impact by adjusting their measurements accordingly. By subtracting 0.01 ft from each recorded measurement conducted at the specified temperature, the systematic error can be effectively compensated for, thereby refining the precision of the surveying process.
This proactive approach not only ensures more accurate measurements but also underscores the importance of identifying and addressing systematic errors in surveying practices to maintain the integrity and reliability of the collected data.
Random Errors In Surveying
In surveying, random errors, also termed accidental errors, occur when a surveyor makes mistakes due to their skill and attention level. These errors are unavoidable because nobody’s perfect. For instance, if a surveyor needs to find point B, which is 109.60 feet away from point A, and their measuring tape is only 100 feet long, they’ll have to set an intermediate point at 100 feet and then measure the remaining 9.60 feet from there. During the process of marking out the 100 feet, the surveyor might make a small mistake and mark it as 99.99 or 99.98 feet.
When measuring the remaining 9.60 feet, there are two more opportunities for errors. The lead surveyor could make the same mistake as before, and the rear surveyor might accidentally hold the tape at a slightly different measurement, like 0.01 feet instead of 0 feet. One essential thing to remember about random errors is that their size is unknown.
Read also: Scan Line Survey
Final Thought
To avoid systematic errors in surveying for construction work, ensure your instruments are properly calibrated and regularly maintained. Additionally, use multiple surveying methods to cross-check measurements.
For random errors, increase sample size and use statistical analysis to identify and correct inconsistencies. Regular training for surveying staff can also help minimize errors.